#include <bits/stdc++.h>
const int MAXN = 100 * 1000;
int a[MAXN + 10];
int dp[MAXN + 10];
int mx = 0;
using namespace std;
int main() {
  long long n, m, k, s = 0;
  cin >> k >> n >> m;
  long long shif = (k - (n % k)) % k;
  n = n + shif;
  if (m < n)
    cout << 0 << endl;
  else
    cout << (m - n) / k + 1 << endl;
}
