/*#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")*/

#include <bits/stdc++.h>
#define bit(n, i) (((n)>>(i))&1)
#define cat(x) cout << #x << " = " << x << "\n"
#define pb push_back
#define mp make_pair
#define se second
#define fi first
#define inf 2000000000
#define llinf 2000000000000000000LL
#define forn(i, a, b) for(ll i = (a); i <= (b); ++i)
#define all(x) (x).begin(), (x).end()
#define ppc(x) __builtin_popcount(x)
using namespace std;
typedef long long ll;
typedef double ld;
typedef pair<int, int> i2;
typedef vector<int> vi;
typedef vector<ll> vll;

/*const ll mod = 167772161;

inline ll add(ll a, ll b) {
    a += b;
    if(a >= mod) a -= mod;
    return a;
}

inline ll sub(ll a, ll b) {
    return add(a, mod-b);
}

inline ll mul(ll a, ll b) {
    return a*b%mod;
}*/

const int N = 1e5+9;
int A[N];
int letter[17][N];
ll dp[17][N], sum[17][N];
ll cost[26];

int n, p, lg, mxcost;

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

    cin >> n;
    int m = n;
    int p = 2;
    while(n % p != 0)
        p++;
    while(n != 1) {
        lg++;
        n /= p;
    }
    n = m;
    forn(i, 0, n-1) {
        char c; cin >> c;
        if(c == '?')
            A[i] = -1;
        else
            A[i] = c-'A';
    }
    int k; cin >> k;
    forn(i, 0, k-1) {
        char c; int v; cin >> c >> v;
        cost[c-'A'] = v;
        mxcost = max(mxcost, v);
    }
    forn(i, 0, n-1) {
        letter[lg][i] = A[i];
        dp[lg][i] = A[i] == -1 ? mxcost : cost[A[i]];
        sum[lg][i] = 1;
    }
    for(int i = lg-1; i >= 0; --i) {
        m /= p;
        for(int j = 0; j < m; ++j) {
            int paint = -1;
            sum[i][j] = n/m;
            for(int l = j; l < m*p; l += m) {
                dp[i][j] += dp[i+1][l];
                sum[i][j] += sum[i+1][l];
                if(letter[i+1][l] == -2) {
                    paint = -2;
                }
                else if(letter[i+1][l] != -1) {
                    if(paint == -1) {
                        paint = letter[i+1][l];
                    }
                    else if(paint != letter[i+1][l]) {
                        paint = -2;
                    }
                }
            }
            if(paint == -1) {
                dp[i][j] = max(dp[i][j], sum[i][j]*mxcost);
            }
            else if(paint != -2) {
                dp[i][j] = max(dp[i][j], sum[i][j]*cost[paint]);
            }
            letter[i][j] = paint;
        }
    }
    cout << dp[0][0];

    return 0;
}