#include"bits/stdc++.h"

using namespace std; 

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef vector<PII> VPII;
typedef long long LL;
typedef vector<LL> VL;
typedef vector<VL> VVL;
typedef pair<LL, LL> PLL;
typedef vector<PLL> VPLL;
typedef priority_queue<LL> PQ_DESC;
typedef priority_queue<LL, VL, greater<LL>> PQ_ASC;
typedef priority_queue<PII> PQ_DESC_PII;
typedef priority_queue<PII, vector<PII>, greater<PII>> PQ_ASC_PII;
typedef priority_queue<VL> PQ_DESC_VL;
typedef priority_queue<VL, vector<VL>, greater<VL>> PQ_ASC_VL;
typedef priority_queue<PLL> PQ_DESC_PLL;
typedef priority_queue<PLL, vector<PLL>, greater<PLL>> PQ_ASC_PLL;

#define ALL(c) (c).begin(),(c).end()
#define PB push_back
#define MP make_pair
#define SORT_ASC(c) sort(ALL(c))
//#define SORT_DESC(c) sort(ALL(c), greater<typeof(*((c).begin()))>())
#define SORT_DESC(c) sort((c).rbegin(),(c).rend())
#define REV(c) reverse((c).begin(), (c).end())
#define SIZE(a) int((a).size())

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define ROF(i,a,b) for(int i=(b-1);i>=(a);--i)
#define REP(i,n) FOR(i,0,n)
#define PER(i,n) ROF(i,0,n)

const double EPS = 1e-10;
const double PI  = acos(-1.0);
const int LARGE_INT = 1e9+100;
const int INF = 2e9+100;
const LL INF_LL = (LL)INF*(LL)INF;
const int MOD = 1e9+7;

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

LL modpow(LL a, LL n) {
    LL res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % MOD;
        a = a * a % MOD;
        n >>= 1;
    }
    return res;
}

void Main()
{
    LL n;cin>>n;
    string s;cin>>s;
    s = "X"+s;

    VL a(n+1);
    VL t(n+1);
    VL c(n+1);
    VL g(n+1);

    FOR(i,1,n+1){
        if(s[i] == 'A'){
            a[i]=1;
        }
        if(s[i] == 'T'){
            t[i]=1;
        }
        if(s[i] == 'C'){
            c[i]=1;
        }
        if(s[i] == 'G'){
            g[i]=1;
        }
        a[i] += a[i-1];
        t[i] += t[i-1];
        c[i] += c[i-1];
        g[i] += g[i-1];
    }

    LL result = 0;
    FOR(i,0,n){
        FOR(j,i+1,n+1){
            LL na = a[j]-a[i];
            LL nt = t[j]-t[i];
            LL nc = c[j]-c[i];
            LL ng = g[j]-g[i];
            if(na==nt && nc==ng){
                result ++;
                //cerr<<i<<" "<<j<<endl;
            }
        }
    }

    cout<<result<<endl;
    
	return;
}

int main()
{
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	cout << fixed << setprecision(15);
	Main();
    return 0;
}
#include <bits/stdc++.h>
using namespace std;

int main() {
    int N;
    string S;
    cin >> N >> S;
    int ans = 0;
    for (int i = 0; i < N; ++i) {
        int c1 = 0, c2 = 0;
        for (int j = i; j < N; ++j) {
            if (S[j] == 'A')
                c1++;
            else if (S[j] == 'T')
                c1--;
            else if (S[j] == 'C')
                c2++;
            else
                c2--;
            if (c1 == 0 && c2 == 0) ans++;
        }
    }
    cout << ans << endl;

    return 0;
}
