#include<bits/stdc++.h>
using namespace std;
string a1,b1;
string str[10],str2[10];
int n=1;
struct node{
	int step;
	string zx;
};
queue<node> q;
set<string> s;
int main(){
	cin>>a1>>b1;
	while(cin>>str[n]>>str2[n])
	{
		n++;
	}
/*	for(int i=1;i<=n;i++)
	{
		cin>>str[i]>>str2[i];
	}*/
	if(a1==b1)
	{
		cout<<0<<endl;
		return 0;
	}
	node cc;
	cc.step=0;
	cc.zx=a1;
	q.push(cc);
	s.insert(a1);/*
	while(!q.empty())
	{
		int stepp=q.front().step;
		string gg=q.front().zx;
		cout<<gg<<' '<<stepp<<endl;
		q.pop();
	}
	*/
	while(!q.empty())
	{
		int stepp=q.front().step;
		string zxx=q.front().zx;
		if(stepp>10)
		{
			cout<<"NO ANSWER!"<<endl;	
			return 0;
		}
		
		for(int i=1;i<=n;i++)
		{
			if(zxx.find(str[i])==-1)
			{
				continue;
			}else
			{
				string ss=zxx;
				ss.replace(zxx.find(str[i]),str[i].length(),str2[i]);
				if(s.count(ss)==0)
				{
					node cc2;
					cc2.step=stepp+1;
					cc2.zx=ss;
					q.push(cc2);
					s.insert(ss);
				}
				if(ss==b1)
				{
					cout<<stepp+1<<endl;
					return 0;
				}
			}
		}
		q.pop();
	}
	cout<<"NO ANSWER!"<<endl;
	return 0;
}