#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define pf push_front
#define pba pop_back
#define pfr pop_front
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
using namespace std;
void fast() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
}
void fre() {
  if(fopen("BAI1.INP", "r")) {
    freopen("BAI1.INP", "r", stdin);
    freopen("BAI1.OUT", "w", stdout);
  }
}
bool check(double x, double y, double z) {
  if(x <= 0 || y <= 0 || z <= 0) return false;
  if((abs(x - y) < z && z < x + y) && (abs(x - z) < y && y < x + z) && (abs(y - z) < x && x < z + y)) return true;
  return false;
}
main() {
  fast();
  fre();
  double x, y, z;
  cin >> x >> y >> z;
  if(check(x, y, z)) cout << "YES";
  else cout << "NO";
}