#include<bits/stdc++.h>
using namespace std;
int bin(string n)
{
    string num = n;
    int dec_value = 0;
    int base = 1;
    int len = num.length();
    for (int i = len - 1; i >= 0; i--)
    {
        if (num[i] == '1')
            dec_value += base;
        base = base * 2;
    }
    return dec_value;
}
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        string s,s1;
        int a,b,cnt=0;
        cin>>s>>s1;
        a=bin(s);
        b=bin(s1);
        while(b!=0)
        {
            int U = a^b;
            int V = a&b;
            a = U;
            b = V * 2;
            cnt++;
        }
        cout<<cnt<<endl;
    }
}