#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

inline int rd() {
    int x = 0;
    bool f = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) f |= (c == '-');
    for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
    return f ? -x : x;
}

#define eb emplace_back
#define all(s) (s).begin(), (s).end()
#define rep(i, a, b) for (int i = (a); i <= (b); ++i)
#define per(i, a, b) for (int i = (a); i >= (b); --i)

const int N = 25000+10;

int n,a[N],cnt[100],lst[100];
char s[N];

int cmp(int a,int b){return a>b;}

inline void work() {
    memset(cnt,0,sizeof(cnt));
    n=rd();
    scanf("%s",s+1);
    for(int i=1;i<=n;++i) {
        if(s[i]>='0'&&s[i]<='9')
            a[i]=s[i]-'0';
        else if(s[i]>='a'&&s[i]<='z')
            a[i]=s[i]-'a'+10;
        else if(s[i]>='A'&&s[i]<='Z')
            a[i]=s[i]-'A'+36;
        cnt[a[i]]++;
        lst[a[i]]=i;
    }
    sort(cnt,cnt+62,cmp);
    int ans=0,sum=0;
    for(int i=0;i<62;++i) {
        if(cnt[i]==0) break;
        sum+=cnt[i];
        ans+=(sum-1)*cnt[i];
    }
    int init=0;
    for(int i=1;i<=n;i++) init+=lst[a[i]]-1;
    printf("%lld\n",1ll*(init-ans)*5);
}

int main() {
    per(t, rd(), 1) work();
    return 0;
}