output_description: If the concatenation of a and b in this order is a square number, print `Yes`;
  otherwise, print `No`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      a b
attempt: #include<bits/stdc++.h>
  using namespace std;
  typedef long long ll;
  #define REP(i, n) for(int i = 0; i < (int)(n); i++)
  
  int main(){
    string a,b;
    cin>>a>>b;
    string num=a+b;
    bool root=false;
    for (int i = 1; i < 101; i++)
    {
      /* code */
      if (i*i==stoi(num))
      {
        /* code */
        root=true;
        break;
      }
      
    }
    if (true)
    {
      /* code */
      cout<<"Yes"<<endl;
    }
    else
    {
      cout<<"No"<<endl;
    }
    
    
    
  }
problem_description: Statement
  
  AtCoDeer the deer has found two positive integers, a and b. Determine whether
  the concatenation of a and b in this order is a square number.
samples: [{"input": "1 21", "output": "Yes\n    \n\nAs 121 = 11 \u00d7 11, it is a square number.\n\n* * *"}, {"input": "100 100", "output": "No\n    \n\n100100 is not a square number.\n\n* * *"}, {"input": "12 10", "output": "No"}]