#include <fstream>
#include <algorithm>

using namespace std;

int n, m, summ;
int dp[1005][1005];
char ch, c;
bool a[27][27];

int main()
{
    ifstream cin("nrcuv.in");
    ofstream cout("nrcuv.out");
    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        cin >> ch >> c;
        a[ch - 'a'][c - 'a'] = true;
        a[c - 'a'][ch- 'a'] = true;
    }
    for(int i = 0; i < 26; i++)
        dp[1][i] = 1;
    for(int i = 2; i <= n; i++)
    {
        for(int j = 0; j < 26; j++)
        {
            for(int k = 0; k < 26; k++)
                if(a[k][j] == false)
                    dp[i][j] += dp[i - 1][k];
        }
    }
    for(int i = 0; i < 26; i++)
        summ += dp[n][i];
    cout << summ;
    return 0;
}