#include <bits/stdc++.h>
int main(void) {
  int A;
  int B;
  int C;
  scanf("%d", &A);
  scanf("%d", &B);
  scanf("%d", &C);
  if (C <= 2 * B + A) {
    printf("YES\n");
  } else {
    printf("NO\n");
  }
  return (0);
}
