#include<stdio.h>

int main()
{
	int m,t,s;
	int lost;
	
    scanf("%d %d %d",&m,&t,&s);
    if(t == 0) return 0;
	if (s >= m*t){
		printf("%d",0);
	}
	else
	lost = m -(s/t);
	printf("%d",lost);
	
	return 0;
	
}