#include<bits/stdc++.h>
using namespace std;
using ll = long long;
//using LL = __int128
#define pi pair<ll, ll>
#define N 1111
ll n, m, a[N], nxt[N], len[N], v[N];
char s[N][N];
int main(){
	scanf("%lld%lld", &m, &n);
	for(int i = 1 ; i <= n ; i++){
		scanf("%s%lld", s[i] + 1, &a[i]);
	}
	if(n == 1){
		n = strlen(s[1] + 1);
		for(int i = 2 ; i <= n ; i++){
			int x = nxt[i - 1];
			while(x && s[1][x + 1] != s[1][i]){
				x = nxt[x];
			}
			if(s[1][i] == s[1][x + 1])
				nxt[i] = (x + 1);
			else
				nxt[i] = 0;
		}
		if(n > m){
			puts("0");
			return 0;
		}
		ll ans = a[1], use = n, add = n - nxt[n];
		while(use + add <= m)
			ans += a[1], use += add;
		printf("%lld", ans);
		return 0;
	}
	if(m <= 10){
		return 0;
	}
	return 0;
}