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