#include <bits/stdc++.h>
using namespace std;

#define NMAX 1005

int main()
{
	freopen("nrcuv.in", "r", stdin);
	freopen("nrcuv.out", "w", stdout);

	int n, m;
	scanf("%d%d", &n, &m);

	bool pairs[26][26] {};

	char x, y;
	int nr_pairs[26] {};
	for (int i = 1; i <= m; ++i) {
		scanf(" %c %c", &x, &y);
		pairs[x - 'a'][y - 'a'] = pairs[y - 'a'][x - 'a'] = 1;
	}

	int dp[NMAX][26];

	for (int j = 0; j < 26; ++j)
		dp[1][j] = 1;


	for (int i = 2; i <= n; ++i)
		for (int j = 0; j < 26; ++j)
			for (int k = 0; k < 26; ++k)
				if (!pairs[j][k])
					dp[i][j] += dp[i - 1][k];

	int ans = 0;

	for (int j = 0; j < 26; ++j)
		ans += dp[n][j];
	
	printf("%d\n", ans);
}