#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
//unordered_map 字符串哈希优化
const int N=6;
string a[N],b[N];
string A,B;
int n;
int extend(queue<string>& q, unordered_map<string, int>&da, unordered_map<string, int>& db, 
    string a[N], string b[N])
{
    int d = da[q.front()];
    while (q.size() && da[q.front()] == d)
    {
        auto t = q.front();
        q.pop();

        for (int i = 0; i < n; i ++ )
            for (int j = 0; j < t.size(); j ++ )
                if (t.substr(j, a[i].size()) == a[i])
                {
                    string r = t.substr(0, j) + b[i] + t.substr(j + a[i].size());
                    if (db.count(r)) return da[t] + db[r] + 1;
                    if (da.count(r)) continue;
                    da[r] = da[t] + 1;
                    q.push(r);
                }
    }

    return 11;
}

int bfs(string A,string B){
    //建立两个方向的队列
    queue<string> qa,qb;
    unordered_map<string,int> da,db;
    qa.push(A),da[A]=0;
    qb.push(B),db[B]=0;
    while (qa.size()&&qb.size()){
        int t;
        if (qa.size()<=qb.size()){
            t=extend(qa,da,db,a,b);
        }else{
            t=extend(qb,db,da,b,a);
        }
        if (t<=10){
            return t;
        }
    }
    return 11;
}
int main(){

    cin>>A>>B;
    if (A==B){
        cout<<0<<endl;
        return 0;
    }
    while (cin>>a[n]>>b[n]) n++;//女少口阿
    int step=bfs(A,B);
    if (step>10){
        cout<<"NO ANSWER!"<<endl;
    }else{
        cout<<step<<endl;
    }
    return 0;
}