#include<iostream>
#include<fstream>
#include<cstring>
using namespace std;
int main()
{
    ifstream fin("nrcuv.in");
    ofstream fout("nrcuv.out");
    long long n,m,x=1,y;
    char v1[2001],v2[2001];
    fin>>n>>m;
    for(int a1=1;a1<=n;a1++) x*=26;
    for(int a1=1;a1<=m;a1++)
    {
        fin>>v1[a1]>>v2[a1];
        for(int a2=1;a2<a1;a2++)
        {
            if((v1[a1]==v1[a2] and v2[a1]==v2[a2]) or (v1[a1]==v2[a2] and v2[a1]==v1[a2])) goto final;
        }
        for(int a3=1;a3<n;a3++)
        {
            if(v1[a1]!=v2[a1]) y=2;
            else y=1;
            for(int a2=a3+1;a2<n-1;a2++)
            {
               y*=26;
            }
            x-=y;
        }
        final:;
    }
    fout<<x;
}