$\color{#1fdb91}{\texttt{C}}\color{#0aaec9}{\texttt{+}}\color{#e9418e}{\texttt{+}}$

#include <iostream> 
#include <cmath> 

using namespace std;

int main() {
  string n; cin >> n;
  int s; for (char c:n) s += c-'0';

  int ss = sqrt(s);
  cout << (ss * ss == s? "YES":"NO");
}

$\\$
\begin{array}{c|c|c}\color{#ffd710}{\texttt{\{}} \color{#8655d6}{\texttt{\{}}\ \ \color{#8cdcda}{\text{Daoanhviet96}}\ \ \color{#8655d6}{\texttt{\}}} \color{#ffd710}{\texttt{\}}}\end{array}

#include <bits/stdc++.h>

using namespace std;

bool scp(int n)
{
    int k=sqrt(n);
    if(k*k==n) return true;
    else return false;
}

int main()
{
    int n,s=0;
    cin>>n;
    while(n!=0)
    {
        s+=n%10;
        n/=10;
    }
    if(scp(s)) cout<<"YES";
    else cout<<"NO";
}