#include<iostream>
#include<array>
#include<algorithm>
#include<string>
#include<map>
#include<queue>
#include<utility>
#define reg register
using namespace std;
using gg=long long;
array<string,6> from,to;
queue<pair<string,gg>> list;
map<string,gg> ans;
int main()
{
	reg gg top=0,t=0;
	reg string beg,res;
	cin>>beg>>res;
	while(cin>>from[top]>>to[top]) top++;
	list.push(make_pair(beg,0));
	ans.insert({beg,0});
	while(!list.empty()&&ans.find(res)==ans.end())
	{
		while(list.front().second==t)
		{
			for(reg gg i=0;i<top;i++)
			{
				string tp=list.front().first;
				gg len=0;
				while(tp.find(from[i],len)!=string::npos)
				{
					len=tp.find(from[i],len);
					tp.replace(len,from[i].size(),to[i]);
					auto fid=ans.find(tp);
					if(fid==ans.end())
					{
						ans.insert({tp,t+1});
						list.push(make_pair(tp,t+1));
					}
					len+=to[i].size()+1;
				}
			}
			list.pop();
		}
		t++;
	}
	if(ans.find(res)==ans.end())
	{
		cout<<"NO ANSWER!\n";
	}
	else
	{
		cout<<(*ans.find(res)).second<<'\n';
	}
	return 0;
}

我感jio我写的很对啊？？？