LIGHTOJ 1010 - Knights in Chessboard

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int r,c,t,result,i=0,f;
    scanf("%d",&t);
    while(t-- && scanf("%d%d",&r,&c)==2)
    {
        if(r==1 || c==1)
        {
            if(r>c)
            {
                result=r;
            }
            else
            {
                result=c;
            }

        }
        else if(r==2 || c==2)
        {
            if(r>c)
            {
                f=r;
            }
            else
            {
                f=c;
            }

            if(r==2 && c==2)
            {
                result=4;
            }
            else if(f%2==0 && f%4!=0)
            {
                result=f+2;
            }
            else if(f%2!=0)
            {
                result=f+1;
            }

        }

        else
        {
            result=ceil((float)(r*c)/2);
        }

        printf("Case %d: %d\n",++i,result);

    }
    return 0;

}