#include <bits/stdc++.h>
using namespace std;
int main() {
  int ap, a, b, c, p = 0, count = 0;
  cin >> a >> b >> c;
  if (a == b) {
    count = 1;
  } else {
    for (int i = 0; i < b - a; i++) {
      ap = a + p;
      if (c % ap == 0) {
        count++;
      }
      p++;
    }
  }
  cout << count << endl;
}
