#include <iostream>
#include <fstream>
using namespace std;

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

int n,m,d[1001][26];
bool ad[26][26];

/*
construiesc d[i][j] = cate cuvinte de lungime i se termina cu a j-a litera din alfabet (d[i][0] = cate se termina cu a, d[i][1]=cate cu b etc.)
d[i][j] = suma dupa 0<=k<26 si k compatibil cu j (ad[k][j] false) din d[i-1][k]
*/

int main()
{
    int i,j,k,r=0;
    char x,y;
    in>>n>>m;
    for(i=1; i<=m; i++)
    {
        in>>x>>y;
        ad[x-'a'+1][y-'a'+1]=1;
        ad[y-'a'+1][x-'a'+1]=1;
    }
    for(i=1;i<=26;i++)
        d[1][i]=1;
    for(i=1; i<=n; i++)
        for(j=1; j<=26; j++)
            for(k=1; k<=26; k++)
                if(ad[j][k]==0)
                {
                    d[i][j]+=d[i-1][k];
                }
    for(i=1;i<=26;i++)
        r=r+d[n][i];
    out<<r;

    return 0;
}