#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
using namespace std;
string temp, b;
int d=0, arr[52], a, total=0;
vector<int> count;
void how_many_different_letters(){
for(int i=0; i<temp.size(); i++){
    if(temp[i]!=temp[i+1])
        d++;
}
}
void turn_arr_to_zero(){
for(int u=0; u<52; u++)
            arr[u]=0;
}
void find_how_many_letters_of_each_type(){
    for(int k=j; k<j+i; k++){
            if(b[k]-'A'<32)
                arr[b[k]-'A']++;
            else
                arr[b[k]-'A'-6]++;
    }
}
void forming_count(){
    for(int u=0; u<52; u++){
        if(arr[u]!=0)
        count.push_back(arr[u]);
    }
}
void checking_if_letter_appear_an_equal_amount_of_times(){
    if(count.size()==d){
        int f=0;
        for(int k=0; k<count.size(); k++){
            if(count[k]!=count[k+1])
                f++;
        }
        if(f==0)
            total++;
    }
}
int main(){
cin>>a;
cin>>b;
temp=b;
sort(temp.begin(), temp.end());
how_many_different_letters();
//cout<<d<<endl;
for(int i=1; i<=a; i++){
    for(int j=0; j<=a-i; j++){
        turn_arr_to_zero();
        find_how_many_letters_of_each_type();
        forming_count();
        checking_if_letter_appear_an_equal_amount_of_times();
    }
}
cout<<total;
return 0;
}