#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, z;
  cin >> x >> y >> z;
  int sum = x;
  int toto = 0;
  if (sum == z) {
    cout << "YES";
    return 0;
  }
  while (sum < z) {
    if (toto % 2 == 0) {
      if (toto == 0) {
        sum += y;
        y--;
      } else
        sum += y;
    } else {
      sum += 1;
    }
    toto++;
    if (sum == z) {
      cout << "YES";
      return 0;
    }
  }
  cout << "NO";
}
