#include<stdio.h>
int main()
{
    int payAmt, accBal, isActive;
    if (scanf("%d", payAmt) !=1)
    {
        printf("Invalid input");
        return 0;
    }
    if (scanf("%d", &accBal) !=1)
    {
        printf("Invalid input");
        return 0;
    }
    if (scanf("%d", &isActive) !=1)
    {
        printf("Invalid input");
        return 0;
    }
    float amt=accBal-payAmt;
    if(isActive ==1)
    {
        if(accBal>payAmt)
        {
            printf("%.2f\n",amt);
        }
        else
        {
            printf("Insufficient Balance\n");
        }
    }
    else if(isActive==0)
    {
        printf("Invalid input\n");
        
    }
    return 0;
    
}