# include <stdio.h>

int main(void)
{
    int m,t,s,n,sum;
    scanf("%d %d %d", &m, &t, &s);
    if(t!=0){
        n=s/t;
        if(s%t!=0){
            n++;
        }
    }
    if(m<=n){
     printf("0");
    }else{
        sum=m-n;
        printf("%d",sum);
        }
        
    if(t=0){
        printf("%d",m);
    }
    return 0;
}