题解

#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,b,c,d;
    cin>>a>>b>>c;
    if(c%b==0) d=c/b;
    else d=c/b+1;
    if(a<=d) cout<<"0";
    else cout<<a-d;
    return 0;
}