#include <bits/stdc++.h>
int main() {
  int a, b, c;
  scanf("%d", &a);
  scanf("%d %d", &b, &c);
  if (a + b <= 1000 && a + b > c && c <= 1000) {
    printf("Yes");
  } else {
    printf("No");
  }
  return 0;
}
