The string t_1t_2 ... t_k is good if each letter of this string belongs to at least one palindrome of length greater than 1.

A palindrome is a string that reads the same backward as forward. For example, the strings A, BAB, ABBA, BAABBBAAB are palindromes, but the strings AB, ABBBAA, BBBA are not.

Here are some examples of good strings: 

  * t = AABBB (letters t_1, t_2 belong to palindrome t_1 ... t_2 and letters t_3, t_4, t_5 belong to palindrome t_3 ... t_5); 
  * t = ABAA (letters t_1, t_2, t_3 belong to palindrome t_1 ... t_3 and letter t_4 belongs to palindrome t_3 ... t_4); 
  * t = AAAAA (all letters belong to palindrome t_1 ... t_5); 



You are given a string s of length n, consisting of only letters A and B.

You have to calculate the number of good substrings of string s.

Input

The first line contains one integer n (1 ≤ n ≤ 3 ⋅ 10^5) — the length of the string s.

The second line contains the string s, consisting of letters A and B.

Output

Print one integer — the number of good substrings of string s.

Examples

Input


5
AABBB


Output


6


Input


3
AAA


Output


3


Input


7
AAABABB


Output


15

Note

In the first test case there are six good substrings: s_1 ... s_2, s_1 ... s_4, s_1 ... s_5, s_3 ... s_4, s_3 ... s_5 and s_4 ... s_5.

In the second test case there are three good substrings: s_1 ... s_2, s_1 ... s_3 and s_2 ... s_3.

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.*;


public class wef {
public static class FastReader {
	BufferedReader br;
	StringTokenizer st;
	//it reads the data about the specified point and divide the data about it ,it is quite fast
	//than using direct 

	public FastReader() {
		br = new BufferedReader(new InputStreamReader(System.in));
	}

	String next() {
		while (st == null || !st.hasMoreTokens()) {
			try {
				st = new StringTokenizer(br.readLine());
			} catch (Exception r) {
				r.printStackTrace();
			}
		}
		return st.nextToken();
	}

	int nextInt() {
		return Integer.parseInt(next());//converts string to integer
	}

	double nextDouble() {
		return Double.parseDouble(next());
	}

	long nextLong() {
		return Long.parseLong(next());
	}

	String nextLine() {
		String str = "";
		try {
			str = br.readLine();
		} catch (Exception r) {
			r.printStackTrace();
		}
		return str;
	}
}
static ArrayList<String>list1=new ArrayList<String>();
static void combine(String instr, StringBuffer outstr, int index,int k)
{
	if(outstr.length()==k)
	{
		list1.add(outstr.toString());return;
	}
	if(outstr.toString().length()==0)
	outstr.append(instr.charAt(index));
    for (int i = 0; i < instr.length(); i++)
    {
        outstr.append(instr.charAt(i));
       
        combine(instr, outstr, i + 1,k);
        outstr.deleteCharAt(outstr.length() - 1);
    }
   index++;
} 
static ArrayList<ArrayList<Integer>>l=new ArrayList<>();
static void comb(int n,int k,int ind,ArrayList<Integer>list)
{
	if(k==0)
	{
		l.add(new ArrayList<>(list));

		return;
	}
	
	
	for(int i=ind;i<=n;i++)
	{
		list.add(i);
		comb(n,k-1,ind+1,list);
		
		list.remove(list.size()-1);
		
	}
	
	
	
	
	

}
static long sum(long n)
{
	long sum=0;
	while(n!=0)
	{
		sum+=n%10;
		n/=10;
	}
	return sum;
}


static boolean check(HashMap<Integer,Integer>map)
{
	for(int h:map.values())
		if(h>1)
			return false;
	return true;
}

static class Pair implements Comparable<Pair>{
    int x;int y;
    Pair(int x,int y){
        this.x=x;
        this.y=y;
      //  this.i=i;
    }
	@Override
	public int compareTo(Pair o) {
		// TODO Auto-generated method stub
		return x-o.x;
		
	}
}
static long ncr(long n, int k) 
{ long m=(long)1e9+7;
    long C[] = new long[k + 1]; 
     
    // nC0 is 1 
    C[0] = 1;   
   
    for (int i = 1; i <= n; i++) 
    { 
        // Compute next row of pascal  
        // triangle using the previous row 
        for (int j = Math.min(i, k); j > 0; j--) 
            C[j] = (C[j]%m + C[j-1]%m)%m; 
    } 
    return C[k]%m; 
} 
static boolean isPrime(int n) 
{ 
    // Corner cases 
    if (n <= 1) 
        return false; 
    if (n <= 3) 
        return true; 
  
    // This is checked so  
    // that we can skip 
    // middle five numbers 
    // in below loop 
    if (n % 2 == 0 ||  
        n % 3 == 0) 
        return false; 
  
    for (int i = 5; 
             i * i <= n; i = i + 6) 
        if (n % i == 0 || 
            n % (i + 2) == 0) 
            return false; 
  
    return true; 
} 
static long pow(long a, long n, long mod) {
	//		a %= mod;
	long ret = 1;
	int x = 63 - Long.numberOfLeadingZeros(n);
	for (; x >= 0; x--) {
		ret = ret * ret % mod;
		if (n << 63 - x < 0)
			ret = ret * a % mod;
	}
	return ret;
}



static int maxsum=0;
static long dp[]=new long[100000];
static long recur(int a[],int ind,int tempsum)
 {
	 if(ind>=a.length)
	 {//System.out.println(tempsum);
		 if(maxsum==0)
			 maxsum=tempsum;
		 else
		 maxsum=Math.max(maxsum, tempsum);
		 return maxsum;
	 }
	 if(dp[ind]!=-1)
		 return dp[ind];
	 
	// System.out.println(tempsum);
	 int ct=0;
	 for(int i=ind;i<ind+(a.length-ind)/2;i++)
	 {ct++;
//	 if(ind+ct<a.length)
	 {	 tempsum+=a[i];
		 
		dp[i]= recur(a,ind+(2*ct),tempsum);}
		 
	 }
	 
	 return dp[ind];
 }
 static int gcd(int a,int b)
 {
	 if(b==0)
		 return a;
	 return gcd(b,a%b);
 }
 static int lcm(int a,int b)
 {
	 return (a*b)/gcd(a,b);
 }
 static HashSet<Long> factorize(long n) {
	    HashSet<Long> facts=new HashSet<Long>();
	    for (long i = 2; i * i <= n; ++i) {
	        while (n % i == 0) {
	            facts.add(i);
	            n /= i;
	        }
	    }
	 
	    if (n != 1) {
	        facts.add(n);
	    }
	    return facts;
	}

public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out));

	public static void main(String[] args) {
		// TODO Auto-generated method stub
	FastReader in=new FastReader();
	TreeMap<Long,Integer>map=new TreeMap<Long,Integer>();
	ArrayList<Long>list=new ArrayList<Long>();
//	HashSet<Integer>set=new HashSet<Integer>();
	HashSet<Integer>dis=new HashSet<Integer>();
	Deque<Integer>qu=new LinkedList<Integer>();
	
	int u=in.nextInt();
		char ch[]=in.next().toCharArray();
		long n=ch.length;
		
		long ct=1;
		
		for(int i=1;i<n;i++)
		{
			if(ch[i]==ch[i-1])
				ct++;
			else
			{
				list.add(ct);
				ct=1;
			}
		}
		list.add(ct);
		ct=0;int y=0;
	for(int i=1;i<list.size()-1;i++)
	{//System.out.println(list.get(i));
		ct+=(2*list.get(i));y++;
	}
	ct-=y;
	ct+=list.get(0);
	ct+=list.get(list.size()-1);
	ct--;
	
	long ans=(n*(n-1))/2-ct;
	if(list.size()>1)
	out.println(ans);
	else
		out.println((n*(n-1))/2);
	out.flush();
	
		
	}
}
