#include <stdio.h>
int main () {
    int amount,th,price;
    printf("请输入票面和价格");
    scanf("%d %d",&amount,&price);
    th=amount-price;
    if(th<0){
        printf("金额不足");
    }
    else{
        printf("需找回%d元",th);
    }


    return 0;
}