#include <iostream>

#include <cstdio>

#include <algorithm>

#include <cstring>

#include <string>

#include <set>

#include <queue>

using namespace std;

string sa, sb;

int n;

struct node

{

    string str;

    int times;

    node()

    {

        str = "";

        times = ;

    }

};

int bfs()

{

    queue<node> q;

    set<string> ss;

    node now , nex;

    now.str = sa;

    q.push(now);

    ss.insert(now.str);

    while(!q.empty())

    {

        now = q.front();

        q.pop();

        if(now.str == sb)

            return now.times;

        for(int i = ; i < n;i++)

        {

            nex.str = now.str;

            nex.times = now.times+;

            nex.str[i] = now.str[];

            nex.str[] = now.str[i];

            if(ss.count(nex.str) == )

            {

                ss.insert(nex.str);

                q.push(nex);

            }

            else

                continue;

        }

    }

}

int main()

{

    cin >> n;

    for(int i =  ; i <  ;i++)

    {

        cin >> sa >> sb;

        cout << bfs() << endl;

    }

    return ;

}