#include <bits/stdc++.h>
using namespace std;
long long ceila(long long a, long long k) {
  if (a % k == 0 || a <= 0)
    return a / k;
  else
    return a / k + 1;
}
long long floora(long long a, long long k) {
  if (a % k == 0 || a >= 0)
    return a / k;
  else
    return a / k - 1;
}
int main() {
  long long k, a, b, t;
  scanf("%lld %lld %lld", &k, &a, &b);
  long long r = floora(b, k) - ceila(a, k);
  r = r < 0 ? -1 : r;
  printf("%lld", r + 1);
  return 0;
}
