#include<cstdio>
#include<cstring>

int main()
{
    int i,t,n,m,ans;
    scanf("%d",&t);
    for(i = 0;i < t;i ++)
    {
        ans = 0;
        scanf("%d%d",&n,&m);
        if(n % 2 == 1)
            ans += (n-1) /2;
        if(n % 2 == 0)
            ans += n / 2;
        if(m % 2 == 1)
            ans += (m-1) / 2;
        if(m % 2 == 0)
            ans += m / 2;
        printf("%d\n",ans);
    }
}