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

int main()
{
  freopen("bai1.inp" , "r" , stdin);
  freopen("bai1.out" , "w" , stdout);
  long double a, b, c;
  cin >> a >> b >> c;
  if (a > 0 and b > 0 and c > 0 and a + b > c and b + c > a and a + c > b)
  {
    cout << "YES";
  }
  else cout << "NO";
}

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

int main(){
    double a,b,c;
    cin>>a>>b>>c;
    if (a>0 && b>0 && c>0 && a+b>c && a+c>b && b+c>a) cout<<"YES";
    else cout<<"NO";
    //meothinhle
    return 0;
}