#include <bits/stdc++.h>;

#include <fstream>

#define INF 100001
#define MOD 104659
using namespace std;

ifstream fin("nrcuv.in");
ofstream fout("nrcuv.out");;

int n, m;
vector<set<int>> cuv(1000);
int val[1005];
int dp[1005][500];
int main()
{


    fin >> n >> m;
    char x, y;
    for (int i = 1; i<=m; i++) {
        fin >> x >> y;
        cuv[x].insert(y);
        cuv[y].insert(x);

        
    }


   
    for (int i = 'a'; i <= 'z'; i++) {
        dp[1][i] = 1;
    }


    for (int i = 2; i <= n; i++) {

        for (int j = 'a'; j <= 'z'; j++) {
            
            for (int k = 'a'; k <= 'z'; k++) {
                if (cuv[j].find(k) == cuv[j].end()) {
                    dp[i][j] += dp[i - 1][k];
                }

            }

        }

    }
    int suma = 0;
    for (int i = 'a'; i <= 'z'; i++) {
        suma += dp[n][i];
    }
    fout << suma;
  
    fin.close();
    fout.close();
    return 0;
}