#include <iostream>
using namespace std;
int main(void) {
int a, b, u, i, num;
cin >> a >> b >> u;
num = 0;
for (i = a; i <= b; i++)
if ((i % u) == 0)
num++;
cout << num << endl;
return 0;
}
输入:1 100 15
输出:1
