diff --git a/Seminars/Seminar05/Self/Task1/Program.cs b/Seminars/Seminar05/Self/Task1/Program.cs
new file mode 100644
index 0000000..205cc92
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task1/Program.cs
@@ -0,0 +1,18 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        for (int i = 1; i <= 50; ++i) {
+            if (i == 20) {
+                continue;
+            }
+            if (i % 2 == 0 && i % 3 == 0) {
+                System.Console.WriteLine(i + " делится на 2 и 3");
+            }
+            else {
+                System.Console.WriteLine(i + "  не делится на 2 и 3");
+            }
+        }
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task10/Program.cs b/Seminars/Seminar05/Self/Task10/Program.cs
new file mode 100644
index 0000000..56cdd04
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task10/Program.cs
@@ -0,0 +1,15 @@
+using System;
+class Program
+{
+    static double G(double x) {
+        if (x <= 0.5) {
+            return Math.Sin(Math.PI / 2);
+        }
+        return Math.Sin(Math.PI * (x - 1) / 2);
+    }
+    static void Main()
+    {
+        double x = double.Parse(Console.ReadLine());
+        System.Console.WriteLine(G(x));
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task2/Program.cs b/Seminars/Seminar05/Self/Task2/Program.cs
new file mode 100644
index 0000000..816b33d
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task2/Program.cs
@@ -0,0 +1,29 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        int kint = 0, kdouble = 0, knan = 0;
+        string s;
+        do {
+            s = Console.ReadLine();
+            int a;
+            double b;
+            bool isint = int.TryParse(s, out a);
+            bool isdouble = double.TryParse(s, out b);
+            if (isint) {
+                ++kint;
+            }
+            else if (isdouble) {
+                ++kdouble;
+            }
+            else {
+                ++knan;
+            }
+        }
+        while (s != "0");
+        System.Console.WriteLine("int = " + kint);
+        System.Console.WriteLine("double = " + kdouble);
+        System.Console.WriteLine("nan = " + knan);
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task3/Program.cs b/Seminars/Seminar05/Self/Task3/Program.cs
new file mode 100644
index 0000000..d0d2376
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task3/Program.cs
@@ -0,0 +1,15 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        double a = double.Parse(Console.ReadLine());
+        int n = int.Parse(Console.ReadLine());
+        double s = 0;
+        for (int i = 1; i <= n; ++i) {
+            double x = a / n * i;
+            s += a / n * x * x;
+        }
+        System.Console.WriteLine(s);
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task4/Program.cs b/Seminars/Seminar05/Self/Task4/Program.cs
new file mode 100644
index 0000000..b03fb4c
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task4/Program.cs
@@ -0,0 +1,16 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        double s = 0;
+        int a = 1, b = 2, c = 3;
+        for (int i = 1; i <= 1000; ++i) {
+            s += 1.0 / (a * b * c);
+            ++a;
+            ++b;
+            ++c;
+        }
+        System.Console.WriteLine(s);
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task5/Program.cs b/Seminars/Seminar05/Self/Task5/Program.cs
new file mode 100644
index 0000000..5f7601c
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task5/Program.cs
@@ -0,0 +1,13 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        int k = int.Parse(Console.ReadLine());
+        double ans = 0;
+        for (int i = 1; i <= k; ++i) {
+            ans += 1.0 / i;
+        }
+        System.Console.WriteLine("{0:F4}", ans);
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task6/Program.cs b/Seminars/Seminar05/Self/Task6/Program.cs
new file mode 100644
index 0000000..81bd636
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task6/Program.cs
@@ -0,0 +1,12 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        for (int i = 100; i <= 999; ++i) {
+            if (i % 10 == i / 10 % 10 && i % 10 == i / 100) {
+                System.Console.WriteLine(i);
+            }
+        }
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task7/Program.cs b/Seminars/Seminar05/Self/Task7/Program.cs
new file mode 100644
index 0000000..5d199c3
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task7/Program.cs
@@ -0,0 +1,15 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        int x = int.Parse(Console.ReadLine());
+        int a = x;
+        while (a > 0) {
+            if (a % 10 != 0) {
+                System.Console.Write(a % 10);
+            }
+            a /= 10;
+        }
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task8/Program.cs b/Seminars/Seminar05/Self/Task8/Program.cs
new file mode 100644
index 0000000..965f5dc
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task8/Program.cs
@@ -0,0 +1,17 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        int x = int.Parse(Console.ReadLine()), k = int.Parse(Console.ReadLine());
+        if (Math.Pow(10, k - 1) <= x) {
+            while (Math.Pow(10, k) <= x) {
+                x /= 10;
+            }
+            System.Console.WriteLine(x);
+        }
+        else {
+            System.Console.WriteLine("wrong input.");
+        }
+    }
+}
diff --git a/Seminars/Seminar05/Self/Task9/Program.cs b/Seminars/Seminar05/Self/Task9/Program.cs
new file mode 100644
index 0000000..73a03b4
--- /dev/null
+++ b/Seminars/Seminar05/Self/Task9/Program.cs
@@ -0,0 +1,11 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        double x = double.Parse(Console.ReadLine()), y = double.Parse(Console.ReadLine());
+        double d = Math.Sqrt(x * x + y * y);
+        bool g = d <= 2 && x >= 0 && x >= y;
+        System.Console.WriteLine(g);
+    }
+}