#include <bits/stdc++.h>

using namespace std;

int N;

string s;

int minn = 0x3f3f3f3f;

int main() {

    scanf("%d", &N);

    cin >> s;

    for(int i = ; i <= N - ; i ++) {

        int cnt = ;

        for(int j = i; j < i + ; j ++) {

            if(j == i) {

                if(s[j] == 'Z') cnt += ;

                else cnt += min(s[j] - 'A', ('Z' - s[j] + ));

            }

            if(j == i + ) cnt += min(abs(s[j] - 'C'), ('Z' - s[j] + ));

            if(j == i + ) cnt += min(abs(s[j] - 'T'), (s[j] - 'A' + ));

            if(j == i + ) cnt += min(abs(s[j] - 'G'), ('Z' - s[j] + ));

        }

        minn = min(minn, cnt);

    }

    printf("%d\n", minn);

    return ;

}

/*

9

AAABBBCCC

*/

#include <bits/stdc++.h>

using namespace std;

const int mod = 1e9 + ;

long long l, r;

long long sum(long long x) {

    if(x <= ) return ;

    int flag = ;

    long long t = ;

    long long sum1 = , sum2 = ;

    for(long long i = ; i < x; ) {

        long long nx = min(i + t, x);

        if(flag) sum1 += (nx - i);

        else sum2 += (nx - i);

        t *= ;

        i = nx;

        flag ^= ;

    }

    long long ans = sum2 % mod * ((sum2 + ) % mod) % mod + sum1 % mod * (sum1 % mod) % mod;

    return ans % mod;

}

int main() {

    cin >> l >> r;

    cout << (sum(r) - sum(l - ) + mod) % mod << endl;

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e5 + ;

int N;

struct Node {

    long long a;

    long long b;

}node[maxn];

bool cmp(const Node &n, const Node &m) {

    return (n.a - n.b) > (m.a - m.b);

}

int main() {

    scanf("%d", &N);

    for(int i = ; i <= N; i ++)

        cin >> node[i].a >> node[i].b;

    sort(node + , node +  + N, cmp);

    long long ans = ;

    for(int i = ; i <= N; i ++)

        ans += (node[i].a * (i - ) + node[i].b * (N - i));

    cout << ans << endl;

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e5 + ;

int N;

long long a[maxn];

int main() {

    scanf("%d", &N);

    for(int i = ; i <= N; i ++)

        cin >> a[i];

    long long ans = ;

    for(int i = ; i <= N; i ++) {

        if(a[i] > a[i - ])

            ans += (a[i] - a[i - ]) * (N - a[i] + );

        else if(a[i] != a[i - ])

            ans += (a[i - ] - a[i]) * a[i];

    }

    cout << ans << endl;

    return ;

}