#include <stdio.h>
int main () {
    float a,b,c;
    printf("顾客实付:");
    scanf("%f",&a);
    printf("商品价格:");
    scanf("%f",&b); 
    c=a-b;
    if(c<0){
        c=-c;
        printf("还需支付%f",c);
    }
    else
    printf("找零:%f",c);
    return 0;
}