#include <bits/stdc++.h>
using namespace std;

int main() {
    int a,b,c;
    float avg=0.0;
    cin>>a>>b>>c;
    avg=(a+b+c)/3.0;
    if(avg<60){cout<<"YES";}
    else{cout<<"NO";}
}

觉得有帮助的话给个免费的赞吧！