#include <bits/stdc++.h>
using namespace std;
int main() {
  long A, B, C;
  cin >> A >> B;
  cin >> C;
  if (A + B > C) {
    cout << "yes";
  } else if (A + B < C) {
    cout << "no";
  }
  return 0;
  return 0;
}
