#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")
using namespace std;
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//~ while (clock()<=69*CLOCKS_PER_SEC)

#define ll long long
#define ld long double
#define pi pair<int,int>
#define pd pair<ld,ld>
#define ft first
#define sd second
#define st first
#define nd second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define FOR(i,a,b) for(int i=(a); i<=(b);i++)
#define F(i,a,b) FOR(i,(a),(b)-1)
#define REV(i,a,b) for(int i=(a); i>=(b);i--)
#define VI vector<int>
#define VPI vector<pi>
#define VPD vector<pd>
#define PI 3.14159265
#define all(x) (x).begin(), (x).end()
#define sz(a) (int)((a).size())
#define int long long

template<class TH> void _dbg(const char *sdbg, TH h){cerr<<sdbg<<"="<<h<<"\n";}
template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) {
    while(*sdbg!=',')cerr<<*sdbg++;cerr<<"="<<h<<","; _dbg(sdbg+1, a...);
}
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const long long K = 1000;
const long long KK = K*K;
const long long MIL = KK*K;
const long long INF = MIL*MIL;
const long long MOD = 167772161;
const long long N = 1e5 + 10, M=10;

bool sito[N];
bool pierwsza[N];

void licz_sito() {
    F(i, 2, N) {
        if (!sito[i]) {
            pierwsza[i] = true;
            for(int j = i * i; j < N; j += i) {
                sito[j] = true;
            }
        }
    }
}

void solve() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    string s1 = s;

    licz_sito();
    VI pierwsze;
    pierwsze.eb(1);
    F(i, 1, n) {
        if (pierwsza[i] && n % i == 0)
            pierwsze.eb(i);
    }

    int k;
    cin >> k;
    map<char, int> let;
    pi najdrozsza(-1, -1);
    F(i, 0, k) {
        char a;
        int v;
        cin >> a >> v;
        let[a] = v;
        najdrozsza = max(najdrozsza, pi{v, a});
    }

    VI dzielniki;
    FOR(i, 1, n) {
        if (n % i == 0) {
            dzielniki.eb(i);
        }
    }

    int res = 0;
    for (int p : pierwsze) {
        bool znalazlo = false;
        F(i, 0, p) {
            bool moze = true;
            for (int j = i; j < n; j += p) {
                moze = moze && (s[j] == '?' || s[j] == s[i]);
            }
            if (moze) {
                znalazlo = true;
                break;
            }
        }

        if (znalazlo) {
            string s2 = s1;

            F(i, 0, p) {
                for(int j = i; j < n; j += p) {
                    if (s2[j] == '?') {
                        s2[j] = s2[i];
                    }
                }
            }

            F(i, 0, n) {
                if (s2[i] == '?')
                    s2[i] = (char)najdrozsza.sd;
            }

            int res2 = 0;
            for (int d : dzielniki) {
                F(i, 0, d) {
                    bool moze = true;
                    for (int j = i; j < n; j += d) {
                        moze = moze && s2[j] == s2[i];
                    }

                    if (moze)
                        res2 += let[s2[i]] * (n / d);
                }
            }

            res = max(res, res2);
        }
    }

    cout << res << "\n";
}

int32_t main()
{
    //	freopen("input.txt", "r", stdin);
    //	freopen("output.txt", "w", stdout);

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cerr.tie(0);
    cout<<setprecision(9)<<fixed;
    cerr<<setprecision(6)<<fixed;
    int test = 1, f;
    //    cin>>test;
    F(_test, 0, test){
        //cout<<"Case #"<<_test + 1<<": ";
        solve();
        //		if(_test == 1)
        //            return 0;
    }

    return 0;
}
/*
3 B
B..
...
...

3 B
BBB
BBB
BBB

3 K
KKK
KKK
KKK
 */