#include <bits/stdc++.h>
int main(void) {
  int A;
  int B;
  int C;
  scanf("%d %d %d", &A, &B, &C);
  if ((C == A + B) || (C <= A + B)) {
    printf("yes\n");
  } else {
    printf("no\n");
  }
  return (0);
}
