#include <bits/stdc++.h>
using namespace std;

#define int long long

const int M = 110;
const int MX = 1e9 + 7;

bool zawiera(string a, string b){
	for(int i = 0; i < (int)a.size(); ++i){
		bool ok = true;
		for(int j = 0; j < (int)b.size(); ++j){
			if(i + j >= (int)a.size()){
				ok = false;
				break;
			}
			
			ok &= a[i + j] == b[j];
		}
		
		if(ok)	return true;
	}
	
	return false;
}

namespace AC{
	const int A = 26;
	const int off = 'a';
	const int MAXN = 110;
	
	int V = 0;
	bool finish[MAXN];
	map <string, int> M;
	
	string st[MAXN];
	int nxt[MAXN][26];
	
	void init(){
		V = 0;
		for(int i = 0; i < MAXN; ++i){
			for(int j = 0; j < 26; ++j)
				nxt[i][j] = 0;
			finish[i] = false;
		}
		
		M[""] = 0;
	}
	
	void add(string s){
		string cur;
		for(auto c: s){
			cur.push_back(c);
			if(!M.count(cur))
				M[cur] = ++V;
		}
		
		finish[M[cur]] = true;
	}
	
	int get(string a){
		while(a.size()){
			if(M.count(a))
				return M[a];
			
			reverse(a.begin(), a.end());
			a.pop_back();
			reverse(a.begin(), a.end());
		}
		
		return 0;
	}
	
	void make(){
		for(auto v: M){
			string tmp = v.first;
			for(char c = 'a'; c <= 'z'; ++c){
				tmp.push_back(c);
				nxt[v.second][c - off] = get(tmp);
				tmp.pop_back();
			}
		}
	}
}

struct matrix{
	int t[M][M];
	matrix(bool id = false){
		for(int i = 0; i < M; ++i)
			for(int j = 0; j < M; ++j)
				t[i][j] = 0;
		
		if(id)
			for(int i = 0; i < M; ++i)
				t[i][i] = 1;
	}
};

matrix operator*(matrix a, matrix b){
	matrix ret;
	for(int i = 0; i < M; ++i)
		for(int j = 0; j < M; ++j)
		{
			ret.t[i][j] = 0;
			for(int k = 0; k < M; ++k)
				ret.t[i][j] = (ret.t[i][j] + 1LL * a.t[i][k] * b.t[k][j]) % MX;
		}
	return ret;
}

int n, q;
string s[M];

matrix fast(matrix a, int b){
	matrix ret(true);
	for(int i = 0; i < M; i++)
		for(int j = 0; j < M; j++)
			ret.t[i][j] = (i == j ? 1 : 0);
	while(b){
		if(b & 1)
			ret = ret * a;
		
		b >>= 1;
		a = a * a;
	}
	
	return ret;
}

int32_t main(){
	cin >> n >> q;
	assert(n > 0 && q > 0);
	AC::init();

	for(int i = 1; i <= q; ++i){
		int xd;
		cin >> xd;
		assert(xd > 0);
		cin >> s[i];
	}	
	
	while(true){
		int id = -1;
		for(int i = 1; i <= q; ++i)
			for(int j = 1; j <= q; ++j)
				if(i != j && zawiera(s[i], s[j])){
					id = i;
					break;
				}
		
		if(id == -1)
			break;
		
		for(int i = id + 1; i <= q; ++i)
			s[i - 1] = s[i];
		q--;
	}
	
	for(int i = 1; i <= q; ++i)
		AC::add(s[i]);
	
	AC::make();
	matrix cur;
	for(int i = 0; i < M; i++)
		for(int j = 0; j < M; j++)
			cur.t[i][j] = 0;
	for(int i = 0; i <= AC::V; ++i){
/*		printf("%d %d :: ", AC::fail[i], AC::finish[i]);
		for(int j = 0; j < 26; ++j)
			printf("%d ", AC::nxt[i][j]);
		puts("");
*/
		if(!AC::finish[i]){
			for(int j = 0; j < 26; ++j)
				cur.t[i][AC::nxt[i][j]]++;
		}
	}
	
	int ret = 0;
	matrix ans = fast(cur, n);
	for(int i = 0; i <= AC::V; ++i)
		if(!AC::finish[i])
			ret = (ret + ans.t[0][i]) % MX;
	cout << ret << "\n";
	return 0;
}