http://acdream.info/problem?pid=1006
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#define ll long long
#define maxn 10000
#define mod 10000000007
using namespace std; double a,b;
int t; int main()
{
scanf("%d",&t);
while(t--)
{
scanf("%lf%lf",&a,&b);
if(a-b>) printf("%.5lf\n",a-);
else printf("%.5lf\n",log2(pow(,a-)+pow(,b-)));
}
return ;
}