#include <stdio.h>

int main() {
    int n, h, m = 0;

    while (scanf("%d %d %d", &n, &h, &m) != EOF) {
        if (m % h != 0) {
            printf("%d\n", n - m / h - 1);
        } else {
            printf("%d\n", n -m / h);
        }
    }
    return 0;
}