diff --git a/Appendix D/solutions/10775.cpp b/Appendix D/solutions/10775.cpp
index 6c991660..e1b6c39d 100644
--- a/Appendix D/solutions/10775.cpp	
+++ b/Appendix D/solutions/10775.cpp	
@@ -1,11 +1,35 @@
-// Authored by : BaaaaaaaaaaarkingDog
+// Authored by : uhwan0723
 // Co-authored by : -
-// http://boj.kr/****************
+// http://boj.kr/0a35dfe1f769483cb900acbd7757b1fb
 #include <bits/stdc++.h>
 using namespace std;
 
+const int mx = 1e5+5;
+int G, P, res, par[mx];
+
+int find(int x){
+  if(par[x] < 0) return x;
+  return par[x] = find(par[x]);
+}
+
+void uni(int x, int y){
+  int u = find(x), v = find(y);
+  if(u == v) return;
+  par[u] = v;
+}
+
 int main(void){
   ios::sync_with_stdio(0);
   cin.tie(0);
-  
-}
\ No newline at end of file
+  cin >> G >> P;
+  fill(par, par+G+5, -1);
+  while(P--){
+    int g;
+    cin >> g;
+    int idx = find(g);
+    if(idx == 0) break;
+    uni(g, idx-1);
+    ++res;
+  }
+  cout << res;
+}