#include<stdio.h>
int main(){
    int a,b,d;
    float c;
    scanf("%d\n%d",&a,&b);
    if(d=1)
        c=b-a;
        if(c>0)
            printf("%.2f",c);
        else
            printf("Insufficient Balance");
    else
        printf("Account is invalid");
    return 0;
}