#include <iostream>
using namespace std;
int main()
{
int ile;
cin>>ile;
int a[ile];
int b[ile];
int x[ile];
int y[ile];
for(int i=0; i<ile; i++)
{
cin>>a[i];
cin>>b[i];
x[i]=a[i];
y[i]=b[i];
}
for(int i=0; i<ile; i++)
{
while(true)
{
if(x[i]>y[i])
{
y[i]=y[i]+b[i];
}
if (x[i]<y[i])
{
x[i]=x[i]+a[i];
}
else
{
cout<<x[i];
cout<<endl;
break;
}
}
}
return 0;
}
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