#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vint = vector<int>;
using pint = pair<int, int>;
const double EPS = 1e-9;
const int inf = numeric_limits<int>::max();
void solve() {
  int A, B, C;
  cin >> A >> B >> C;
  if ((A + B) * 2 >= C) {
    cout << "Yes";
  } else {
    cout << "No";
  }
  cout << endl;
}
int main() {
  solve();
  return 0;
}
