#include <iostream>
#include <string>
#include <queue>

using namespace std;

const int N = 15;

struct node
{
	string str;
	int plies;
};

string a, b;
string t1[N], t2[N];
int cnt = 1;
queue <string> q;
queue <int> p;
int ans = 0x7fffffff;

int main()
{
	cin >> a >> b;

	while (cin >> t1[cnt] >> t2[cnt])
	{
		cnt++;
	}

	q.push(a);
	p.push(0);
	while (!q.empty() && !p.empty())
	{
		string tmp = q.front();
		int tp = p.front();
		
		if (tmp == b || tp > 10)
		{
			ans = tp;
			
			//q.pop();
			//p.pop();

			break;

			//continue;
		}

		for (int i = 1; i < cnt; i++)
		{
			string m = tmp;
			int pos = 0;
			while (m.find(t1[i], pos) != m.npos)
			{
				pos = m.find(t1[i], pos);
				m = m.replace(pos, t1[i].size(), t2[i]);

				q.push(m);
				p.push(tp + 1);

				pos++;

				m = tmp;
			}
		}

		q.pop();
		p.pop();
	}

	if (ans >= 0 && ans <= 10)
	{
		cout << ans;
	}
	else
	{
		cout << "NO ANSWER!";
	}

	return 0;
	//p:
}

rt