2640: More Vertexes, More Area

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int n,m,s;
    while(scanf("%d%d",&n,&m),n||m)
    {
  if(n==1||m==1) {printf("0/n");continue;}
        if(n%2==1&&m%2==1)
        {
            if(n<m) swap(n,m);
            s=(n-2)*(m-1)/2+(m-2)+(n-1)/2+1;
        }
        else
        {
            if(n%2==1) swap(n,m);
            s=(m-2)*n/2+n-1;
        }
        printf("%d/n",s);
    }
    return 0;
}