#include<cstring>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<stdio.h>
#include<cmath>
#include<iomanip>
using namespace std;
int main(){
	int a,s,d,k=0;
	cin>>a>>s>>d;
	if(d!=0){
		if(d/s%1==0){
			d=d/s;
		}else{
			while(k*s%1==0||k*s<d/s){
				k++;
			}
			k+1;
		}
	}
	if(k==0){
		cout<<a-d;
	}else{
		cout<<a-k;
	}
	
	return 0;
}