#include<bits/stdc++.h> using namespace std; bool k(int m){ for(int i=2;i<=sqrt(m);i++){ if(m%i==0) return false; } return true; } int main(){ int n; cin>>n; for(int i=2;i<=sqrt(n);i++){ if(k(i)&&k(n/i)&&i*(n/i)==n){ cout<<"It's a Tongtong number."; return 0; } } cout<<"It's not a Tongtong number."; } /************************************************************** Problem: 1151 User: wangyiyang Language: C++ Result: Accepted Time:7 ms Memory:2072 kb ****************************************************************/