#include<cstdio>
using namespace std;

int n, m;
int is[30][30], p[1001][30];

int main() {
	int i, j, k, rez = 0;
	char c1, c2;
	freopen("nrcuv.in", "r", stdin);
	freopen("nrcuv.out", "w", stdout);
	scanf("%d %d", &n, &m);
	for(i = 1; i <= m; ++i) {
		scanf("%c %c %c", &c1, &c1, &c2);
		is[(int)c1 - 'a' + 1][(int)c2 - 'a' + 1] = 1;
		is[(int)c2 - 'a' + 1][(int)c1 - 'a' + 1] = 1;
	}
	
	for(i = 1; i <= 26; ++i)
		p[1][i] = 1;
	for(i = 2; i <= n; ++i) 
		for(j = 1; j <= 26; ++j)
			for(k = 1; k <= 26; ++k)
				if(!is[j][k])
					p[i][j] += p[i - 1][k];
	
	for(i = 1; i <= 26; ++i)
		rez += p[n][i];
	
	printf("%d\n", rez);
	
	return 0;
}