Div 1 Problem A

#include<stdio.h>
int main()
{
      double a,r,s;
      int n,t,j,i;
      while(scanf("%d",&t)==1)
      {
            j=0;
            while(t--)
            {
                  scanf("%lf%d",&r,&n);

                  printf("Case %d: ",++j);
                  a=r/80;
                  s=.2/12;
                  for(i=1;i<=n;i++)
                  {
                     a=a+a*s;
                  }
                  a=a*79;
                  printf("%.2lf\n",a);
            }
      }
      return 0;
}