#include<bits/stdc++.h>
using namespace std;
string s1,s2;
string r1[15],r2[15];
int len1[15];
int k,fi;
int len;
map<string,int> flag,mark;
queue<string> q[5];
int doublebfs(){
	flag[s1]=0;
	flag[s2]=0;
	mark[s1]=1;
	mark[s2]=2;
	q[1].push(s1);
	q[2].push(s2);
	string x,y;
	int fx;
	while(!q[1].empty()&&!q[2].empty()){
		if(q[1].size()>q[2].size()) fx=2;
		else fx=1;
		x=q[fx].front();
		q[fx].pop();
		if(flag[x]>10) continue;
		for(int i=1;i<=k;i++){
			int ft=0;
			while(ft<=len){
				int fi=x.find(r1[i],ft);
				if(fi!=-1){
					y=x;
					y.replace(fi,len1[i],r2[i]);
					//cout<<y<<" "<<i<<" "<<fx<<endl;
					if(mark[x]&&mark[y]&&mark[x]!=mark[y]){
						int t=flag[x]+flag[y]+1;
						if(t>10) continue;
						return t;
					}
					if(!mark[y]){
						mark[y]=mark[x];
						flag[y]=flag[x]+1;
						q[fx].push(y);
					}
				}else break;
				ft=fi+1;
			}
		}
	}
	return -1;
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>s1>>s2;
	for(int i=1;i<=6;i++){
		cin>>r1[i]>>r2[i];
		len1[i]=r1[i].size();
	}
	for(int i=1;i<=6;i++){
		if(!len1[i]){
			break;
		}
		k=i;
	}
	len=s1.size();
	int dn=doublebfs();
	if(dn==-1) cout<<"NO ANSWER!";
	else cout<<dn;
	return 0;
}

双端队列40分 求daolao调教