#include <bits/stdc++.h>
int main() {
  int a, b, c, count = 0;
  scanf("%d,%d,%d", &a, &b, &c);
  for (int i = a; i < (b + 1); i++) {
    if ((c / i) == 0) count++;
  }
  printf("%d\n", count);
  return 0;
}
