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