#include<stdio.h>
int main()
{
	int m, t, s, apple;
	scanf("%d%d%d", &m, &t, &s);
	if (t == 0) {
		printf("0");
	}
	if (t != 0) {
		apple = m - s / t;
		if (apple < 0) {
			printf("0");
		}
		else {
			printf("%d", apple);
		}
	}
	return 0;
}