#include <iostream>
#include <stdio.h>
#include <math.h>
#include <algorithm>
#include <string.h>
#include <map>

using namespace std;

struct Node
{
    string x;
    int step;
};
Node q[100005];

const int MAXN = 1005;
int cnt = 0, step, front, rear; 
string n, m, a[MAXN], b[MAXN];
map<string, bool> vis; //作用等同于數組中的vis數組 

int bfs()
{
    Node now;
    now.x = n;
    now.step = 0;
    front = rear = 0;
    q[rear] = now;
    rear++;
    while(front < rear)
    {
        now = q[front++];
        if(now.x == m)
        {
            cout << now.step << endl;
            return 0;
        }
        if(now.step > 10)
        {
            return -1;
        }
        for(int i = 0; i < cnt; i++)
        {
            string temp = now.x;
            int pos = temp.find(a[i]);
            while(pos != -1) 
            {
                temp.replace(pos, a[i].length(), b[i]); //做變換 = pos 
                if(vis[temp] == 0) 
                {
                    vis[temp] = true;
                    q[rear].x = temp;
                    q[rear].step = now.step + 1;
                    rear++;
                }
                temp = now.x; 
                pos = temp.find(a[i], pos + 1); // 從下一個位置查找，做一次變換
            }
        } 
    }
    return -1;
}
    
int main()
{
    cin >> n >> m;
    cnt = 0;
    while(cin >> a[cnt] >> b[cnt])
    {
        cnt++;
    }
    if(bfs() < 0)
    {
        cout << "NO ANSWER!" << endl;
    }
    return 0;
}