#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define ZERO (1e-10)
#define INF int(1e9+1)
#define CL(A,I) (memset(A,I,sizeof(A)))
#define DEB printf("DEB!\n");
#define D(X) cout<<"  "<<#X": "<<X<<endl;
#define EQ(A,B) (A+ZERO>B&&A-ZERO<B)
typedef long long ll;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
#define IN(n) int n;scanf("%d",&n);
#define FOR(i, m, n) for (int i(m); i < n; i++)
#define F(n) FOR(i,0,n)
#define FF(n) FOR(j,0,n)
#define FT(m, n) FOR(k, m, n)
#define aa first
#define bb second
void ga(int N,int *A){F(N)scanf("%d",A+i);}
#define MX (106)
#define AL (26)
int g[MX][AL],f[MX],E,q[MX],O[MX];
void ini(){E=1;F(AL)g[0][i]=0;CL(f,0),CL(O,0);}
void add(char*s){
    int L=strlen(s),u=0,c;
    F(L){
        if(!g[u][c=s[i]-97]){
            g[u][c]=E++;
            F(AL)g[E-1][i]=0;
        }
        u=g[u][c];
    }
    O[u]=1;
}
void bld(){
    int x,r,b=-1,e=0,u;
    F(AL)if(g[0][i])f[g[0][i]]=0,q[e++]=g[0][i];
    while(++b<e)F(AL){
        x=g[u=q[b]][i],r=g[f[u]][i];
        if(!x)g[u][i]=r;
        else{
            q[e++]=x,f[x]=r;
            O[x]|=O[r];
        }
    }
}
#define MM (MX)
void mul(int A[MM][MM],int B[MM][MM],int R[MM][MM],int W,int M){
    F(W)FF(W)R[i][j]=0;
    F(W)FF(W){
        ll D=M*1ll*M,S=0;;
        FT(0,W)if((S+=A[i][k]*1ll*B[k][j])>=D)S-=D;
        R[i][j]=S%M;
    }
}
void pw(int M[MM][MM],int R[MM][MM],int W,ll k,int MD){
    static int E[MM][MM],H[MM][MM];
    F(W)FF(W)R[i][j]=E[i][j]=i==j;
    while(k){
        if(k&1)mul(E,M,R,W,MD),memcpy(E,R,sizeof(E));
        mul(M,M,H,W,MD);
        memcpy(M,H,sizeof(H));
        k>>=1;
    }
}
#define MOD 1000000007
ll pw(ll n,ll k){
    ll r(1);
    while(k){
        if(k&1)r*=n,r%=MOD;
        n*=n,n%=MOD;
        k>>=1;
    }
    return r;
}
char s[MX];
int L,N,Q,M[MX][MX],R[MX][MX];
int main(void){
    scanf("%d%d",&N,&Q),ini();
    F(Q){
        scanf("%*d%s",s);
        add(s);
    }
    bld();
    F(E)FF(26)if(O[g[i][j]])++M[i][E];
              else ++M[i][g[i][j]];
    M[E][E]=26;
    pw(M,R,E+1,N,MOD);
    printf("%lld\n",(pw(26,N)-R[0][E]+MOD)%MOD);
    return 0;
}