#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define ll long long
#define lll __int128
#define ull unsigned long long
#define fi first
#define se second
#define db double
#define ld long double
#define lld __float128

/// order_of_key, find_by_order

template<class T, class COMP>
using custom_set = tree<T, null_type, COMP, rb_tree_tag, tree_order_statistics_node_update>;

template<class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

template<class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

template<class T, class U>
using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rnd_64(chrono::steady_clock::now().time_since_epoch().count());

ll cst[27], mx;
vector<char> ctg;

ll dvd, pw;

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n; cin >> n;
    for(int i = 2; i <= n; i++)
    {
        if(n % i == 0)
        {
            dvd = i; break;
        }
    }
    int N = n;
    while(N > 1)
    {
        pw++; N /= dvd;
    }
    string s; cin >> s;
    int k; cin >> k;
    for(int i = 0; i < k; i++)
    {
        char c; cin >> c;
        ctg.push_back(c);
        cin >> cst[c-'A'];
        mx = max(mx, cst[c-'A']);
    }
    ll ans = 0, vl = 1;
    for(int i = 0; i <= pw; i++)
    {
        ll res = 0;
        for(int st = 0; st < vl; st++)
        {
            bool good = 1;
            char c = '#';
            for(int j = st; j < n; j += vl)
            {
                if(s[j] != '?')
                {
                    if(c == '#')
                        c = s[j];
                    else if(c != s[j])
                    {
                        good = 0; break;
                    }
                }
            }
            if(!good)
                continue;
            if(c != '#')
            {
                res += (pw-i+1) * cst[c-'A']*n/vl;
            }
            else
            {
                res += (pw-i+1) * mx*n/vl;
            }
        }
        ans = max(ans, res);
        vl *= dvd;
       // cout << ans;
    }
    cout << ans;
}






































/// shche ne vmerla Ykraina