#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, z;
  cin >> x >> y >> z;
  vector<int> vec;
  if (x == z) vec.push_back(x);
  while (true) {
    if (x + y == z) {
      vec.push_back(x + y);
      break;
    } else if (x + y + 1 == z) {
      vec.push_back(x + y + 1);
      break;
    }
    x += y;
    if (z < x) break;
  }
  if (!vec.empty()) {
    cout << "YES" << endl;
    return 0;
  }
  cout << "NO" << endl;
  return 0;
}
