#include <cstdio>

using namespace std;

int a[27][27],w[27][27],c[27][27],n,m;

void inmultire(int a[27][27], int b[27][27], int c[27][27])
{
    for (int i=1; i<=26; i++)
        for (int j=1; j<=26; j++)
        {
            c[i][j]=0;
            for (int k=1; k<=26; k++)
                c[i][j]+=a[i][k]*a[k][j];
        }
}

void copiere(int a[27][27],int w[27][27])
{
    for (int i=1; i<=26; i++)
        for (int j=1; j<=26; j++)
            w[i][j]=a[i][j];
}

void inm_log(long long i,int w[27][27])
{
    if (i==1)
        copiere(a,w);//%MAX;
    else
    if (i%2==0)
    {
        inm_log(i/2,w);
        inmultire(w,w,w);//(aux*aux)%MAX;
    }
    else
    {
        inm_log(i-1,w);
        inmultire(a,w,w);
    }
}

void citire()
{
    char x,y;
    for (int i=1; i<=26; i++)
        for (int j=1; j<=26; j++)
            a[i][j]=1;
    freopen("nrcuv.in","r",stdin);
    scanf("%d %d\n", &n, &m);
    for (int i=0; i<m; i++)
    {
        scanf("%c %c\n", &x, &y);
        a[x-'a'+1][y-'a'+1]=a[y-'a'+1][x-'a'+1]=0;
    }
}

int main()
{
    freopen("nrcuv.out","w",stdout);
    citire();
    inm_log(n-1,w);
    int s=0;
    for (int i=1; i<=26; i++)
        for (int j=1; j<=26; j++)
            s+=w[i][j];
    printf("%d\n",s);
    return 0;
}