#include <bits/stdc++.h>
using namespace std;
void solve()
{
int a,b;
cin>>a>>b;
int x,y,z,p;
x=500-(a*2);
y=1000-(b*4);
z=x+y;
cout<<z<<"\n";
}
int main()
{
int g;
cin>>g;
for(int i=0;i<g;i++)
{
solve();
}
return 0;
}
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