#include <bits/stdc++.h>
using namespace std;
string A, B;
int n;
string a[25], b[25];
map<string, int> dis;
queue<string> q;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> A >> B;
    n = 1;
    while (cin >> a[n] >> b[n])
        n++;
    n--;

    dis[A] = 0;
    q.push(A);
    while (!q.empty())
    {
        string now = q.front();
        q.pop();
        for (int t = 1; t <= n; t++)
        {
            for (int i = 0; i + a[t].size() - 1 < now.size(); i++)
            {
                bool flag = true;
                for (int j = i; j < i + a[t].size(); j++)
                    if (now[j] != a[t][j - i])
                    {
                        flag = false;
                        break;
                    }
                if (flag)
                {
                    string nxt = "";
                    for (int j = 0; j < i; j++)
                        nxt += now[j];
                    nxt += b[t];
                    for (int j = i + a[t].size(); j < now.size(); j++)
                        nxt += now[j];
                    if (dis.find(nxt) == dis.end())
                    {
                        dis[nxt] = dis[now] + 1;
                        q.push(nxt);
                        if (nxt == B)
                        {
                            cout << dis[nxt] << "\n";
                            return 0;
                        }
                    }
                }
            }
        }
    }
    cout << "NO ANSWER!";
    return 0;
}