#include <bits/stdc++.h>
using namespace std;
const int MaxN = 1e5 + 17;
const int INF = 1e9 + 17;
long long a, t, s;
int main() {
  cin >> t >> s >> a;
  int l = 1, r = INF;
  if (t == a) cout << "YES", exit(0);
  while (l <= r) {
    long long m = (l + r) >> 1;
    if (t + m * s <= a) {
      if (t + m * s == a || t + m * s == a - 1) cout << "YES", exit(0);
      l = m + 1;
    } else
      r = m - 1;
  }
  cout << "NO";
  return 0;
}
