@@ -0,0 +1,11 @@
+#include<bits/stdc++.h>
+using namespace std;
+int main(){
+ int n;cin>>n;
+ int m=sqrt(n);
+ int left=m*m,right=(m+1)*(m+1);
+ if(m-left<right-m)cout<<left<<endl;
+ else cout<<right<<endl;
+
+ return 0;
+}
