#include<stdio.h>
#include<math.h>
int main(){
	int m,t,s;
	scanf("%d%d%d",&m,&t,&s);
	if(t==0){
		printf("0");
	}else if(s%t==0){
		int a = m-s/t;
		printf("%d",a);
	}else{
		int a = m-s/t-1;
		printf("%d",a);
	}
	return 0;
}