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

#define int long long

const int M = 150;
const int MX = 1000 * 1000 * 1000 + 7;

namespace AC{
	const int A = 26;
	const int off = 'a';
	const int MAXN = 150;
	
	int V = 0;
	int 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;
	}
	
	bool check(string a){
		while(a.size()){
			if(M.count(a) && finish[M[a]])
				return true;
			
			reverse(a.begin(), a.end());
			a.pop_back();
			reverse(a.begin(), a.end());
		}
		
		return false;
	}
	
	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();
			}
			
			if(tmp.size()){
				finish[v.second] |= check(tmp);
				tmp.pop_back();
				finish[v.second] |= finish[M[tmp]];
			}
		}
	}
}

typedef long long LL;
typedef vector < vector < LL > > matrix;

matrix operator* (matrix a, matrix b)
{
	int n = a.size();
	matrix r(n, vector < LL > (n, 0));
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			for(int k = 0; k < n; k++)
			{
				r[i][j] = (r[i][j] + a[i][k] * b[k][j]) % MX;
			}
		}
	}
	return r;
}

matrix fast(matrix a, int y)
{
	assert(y > 0);
	matrix r = a;
	y--;
	
	while(y > 0)
	{
		if(y & 1) r = r * a;
		a = a * a;
		y /= 2;
	}
	return r;
}

int n, q;
string s[M];

int32_t main(){
	cin >> n >> q;
	assert(n > 0 && q > 0);
	AC::init();
	
	int sum = 0;
	for(int i = 1; i <= q; ++i){
		int xd;
		cin >> xd;
		assert(xd > 0);

		cin >> s[i];
		for(auto c: s[i])
			assert('a' <= c && c <= 'z');
		assert((int)s[i].size() == xd);
		sum += xd;
	}	
	
	assert(sum <= 100);
	for(int i = 1; i <= q; ++i)
		AC::add(s[i]);
	
	AC::make();
	int zz = AC::V + 1;
	matrix cur(zz, vector <LL> (zz, 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[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[0][i]) % MX;
	assert(0 <= ret && ret < MX);
	cout << ret << "\n";
	return 0;
}