#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;
using ll = long long;
using P = pair<int, int>;
const int MOD = 1000000007;
template <class T>
void print(const T& t) {
  cout << t << endl;
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int main() {
  ll a, b, c;
  cin >> a >> b >> c;
  if (2 * (a + b) >= c) {
    print("Yes");
  } else {
    print("No");
  }
}
