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.*;
import java.util.*;
import java.text.*;
import java.lang.*;
import java.math.*;
 
public class just{
	
	
	 public void solve () {
	    	InputReader in =new InputReader(System.in);
	    	PrintWriter pw = new PrintWriter(System.out);
	    	long n=in.nextLong();
	    	char s[]=in.nextLine().toCharArray();
	    	long cnt=1;
	    	Vector<Long>v=new Vector<>();
	    	for(int i=1;i<n;i++) {
	    		if(s[i]!=s[i-1]) {
	    			v.add(cnt);
	    			cnt=1;
	    			continue;
	    		}
	    		cnt++;
	    	}
	    	v.add(cnt);
	    	long ans = (n*(n-1))/2L;
	    	for(int i=1;i<v.size();i++) {
	    		ans-=(v.get(i)+v.get(i-1)-1);
	    	}
	    	pw.print(ans);
	    	pw.flush();
	    	pw.close();
	    	
	 }
    public static void main(String[] args) throws Exception {
    	new Thread(null,new Runnable() {
            public void run() {
                new just().solve();
            }
        },"1",1<<26).start();
    	
    }
   
    static void debug(Object... o) {
        System.out.println(Arrays.deepToString(o));
        }
        
        static class InputReader 
        {
        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;
 
        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }
        public int snext() 
        {
            if (snumChars == -1)
                throw new InputMismatchException();
            if (curChar >= snumChars) 
            {
                curChar = 0;
                try 
                {
                    snumChars = stream.read(buf);
                } 
                catch (IOException e) 
                {
                    throw new InputMismatchException();
                }
                if (snumChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }
 
        public int nextInt() 
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = snext();
            }
            int res = 0;
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public long nextLong()
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') 
            {
                sgn = -1;
                c = snext();
            }
            long res = 0;
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public int[] nextIntArray(int n) 
        {
            int a[] = new int[n];
            for (int i = 0; i < n; i++) 
            {
                a[i] = nextInt();
            }
            return a;
        }
 
        public String readString()
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = snext();
            } while (!isSpaceChar(c));
            return res.toString();
        }
 
        public String nextLine() 
        {
            int c = snext();
            while (isSpaceChar(c))
                c = snext();
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = snext();
            } while (!isEndOfLine(c));
            return res.toString();
        }
 
        public boolean isSpaceChar(int c) 
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
        private boolean isEndOfLine(int c) 
        {
            return c == '\n' || c == '\r' || c == -1;
        }
 
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
        public static long mod = 1000000007;
        public static int d;
        public static int p;
        public static int q;
        public void extended(int a,int b) {
            if(b==0) {
                d=a;
                p=1;
                q=0;
            }
            else
            {
                extended(b,a%b);
                int temp=p;
                p=q;
                q=temp-(a/b)*q;
            }
        }
        public static int binaryExponentiation(int x,int n)
        {
            int result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=result * x;
                x=x*x;
                n=n/2;
            }
            return result;
        }
        
        public static long binaryExponentiation(long x,long n)
        {
            long result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=result * x;
                x=x*x;
                n=n/2;
            }
            return result;
        }
        
        public static long[] shuffle(long[] a,Random gen)
        {
            int n = a.length;
            for(int i=0;i<n;i++)
            {
                int ind = gen.nextInt(n-i)+i;
                long temp = a[ind];
                a[ind] = a[i];
                a[i] = temp;
            }
            return a;
        }
        
        public static void swap(int a, int b){
            int temp = a;
            a = b;
            b = temp;
        }
        
        public static HashSet<Integer> primeFactorization(int n)
        {
            HashSet<Integer> a =new HashSet<Integer>();
            for(int i=2;i*i<=n;i++)
            {
                while(n%i==0)
                {
                    a.add(i);
                    n/=i;
                }
            }
            if(n!=1)
                a.add(n);
            return a;
        }
        
        public static void sieve(boolean[] isPrime,int n)
        {
            for(int i=1;i<n;i++)
                isPrime[i] = true;
            
            isPrime[0] = false;
            isPrime[1] = false;
            
            for(int i=2;i*i<n;i++)
            {
                if(isPrime[i] == true)
                {
                    for(int j=(2*i);j<n;j+=i)
                        isPrime[j] = false;
                }
            }
        }
        
        public static long GCD(long n,long m)
        {
            if(m==0)
                return n;
            else
                return GCD(m,n%m);
        }
        
        static class pair implements Comparable<pair>
        {
          Long x,y,z;
            pair(long l,long m,long n)
            {
                this.x=l;
                this.y=m;
                this.z=n;
            }
 
           
 
			public int compareTo(pair o) {
                int result = x.compareTo(o.x);
                if(result==0)
                    result = y.compareTo(o.y);
                
                return result;
            }  
            
            public String toString()
            {
                return (x)+" "+(y)+" "+z;
            }
            
            public boolean equals(Object o)
            {
                if (o instanceof pair)
                {
                    pair p = (pair)o;
                    return p.x.equals(x) && p.y.equals(y) ;
                }
                return false;
            }
            
            public int hashCode()
            {
                return new Long(x).hashCode()*31 + new Long(y).hashCode();
            }
        }
        public static int modularExponentiation(int x,int n,int M)
        {
            int result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=(result * x)%M;
                x=(x%M*x)%M;
                n=n/2;
            }
            return result;
        }
        
        public static long modularExponentiation(long x,long n,long M)
        {
            long result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=(result%M * x%M)%M;
                x=(x%M * x%M)%M;
                n=n/2;
            }
            return result;
        }
        
        public static long modInverse(int A,int M)
        {
            return modularExponentiation(A,M-2,M);
        }
        
        public static long modInverse(long A,long M)
        {
            return modularExponentiation(A,M-2,M);
        }
               
    
}
 
class dsu{
    int parent[];
    long sz[];
    dsu(int n){
        parent=new int[n+1];
        sz=new long[n+1];
        for(int i=0;i<=n;i++)
        {
            parent[i]=i;
            sz[i]=1;
        }
    }
    int root(int n) {
        while(parent[n]!=n)
        { 
            parent[n]=parent[parent[n]];
            n=parent[n];
        }
        return n;
    }
    void union(int _a,int _b) {
        int p_a=root(_a);
        int p_b=root(_b);
        
        parent[p_a]=p_b;
        sz[p_b]+=sz[p_a];
            
    }
    long find(int a,int b) {
    	int root_a=root(a);
    	int root_b=root(b);
        if(root_a==root_b)
            return 0;
        else
            return  sz[root_a]*sz[root_b];
    }
    
    
}
class Segment{ 
    long seg[];
    Segment (int n){
        seg=new long[4*n];
       
    }
    public void build(int node,int start,int end) {
        if(start==end) {
            seg[node]=0L;
            return ;
        }
        int mid=(start+end)/2;
        build(2*node+1,start,mid);
        build(2*node+2,mid+1,end);
    }
    
   
    public void update(int node,int start,int end,int fi,long val) {
        if(start==end) {
            seg[node]+=val;
            return;
        }
        int mid=(start+end)/2;
        if(fi>=start && fi<=mid) {
            update(2*node+1,start,mid,fi,val);
        }
        else
            update(2*node+2,mid+1,end,fi,val);
        seg[node]=(seg[2*node+1]+seg[2*node+2]);
    }
    public long query(int node,int start,int end,int l,int r) {
        if(l>end || r<start)
            return 0;
        if(start>=l && end<=r)
            return seg[node];
        
        int  mid=(start+end)/2;
        return (query(2*node+1,start,mid,l,r)+query(2*node+2,mid+1,end,l,r));
    }
    /*public void updateRange(int node,int start,int end,int l,int r,int val) {
        if(lazy[node]!=0) {
            seg[node]-=lazy[node];
            if(start!=end) {
                lazy[2*node+1]+=lazy[node];
                lazy[2*node+2]+=lazy[node];
            }
            lazy[node]=0;
        }
        if(l>end || r<start)
            return ;
        if(start>=l && end<=r) {
            seg[node]-=val;
            if(start!=end) {
                lazy[2*node+1]+=val;
                lazy[2*node+2]+=val;
            }
            return ;
        }
        int mid=(start+end)/2;
        updateRange(2*node+1,start,mid,l,r,val);
        updateRange(2*node+2,mid+1,end,l,r,val);
        seg[node]=Math.min(seg[2*node+1],seg[2*node+2]);
    }
    public long queryRange(int node,int start,int end,int l,int r) {
        if(lazy[node]!=0L) {
            seg[node]-=lazy[node];
            if(start!=end) {
                lazy[2*node+1]+=lazy[node];
                lazy[2*node+2]+=lazy[node];
            }
            lazy[node]=0;
        }
        if(l>end || r<start)
            return Long.MAX_VALUE;
        if(start>=l && end<=r)
            return seg[node];
        
        int  mid=(start+end)/2;
        return Math.min(queryRange(2*node+1,start,mid,l,r),queryRange(2*node+2,mid+1,end,l,r));
    }*/
    
}
