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.*;
 
 
 
public class Main {
	
	static InputReader in = new InputReader(System.in);
	static PrintWriter out = new PrintWriter(System.out);
	
	static int oo = (int)1e9;
	static int mod = 1_000_000_007;
	
	static int[] di = {1, 0, 0, -1};
	static int[] dj = {0, -1, 1, 0};
	
 
	
	public static void main(String[] args) throws IOException {

		int n = in.nextInt();
		char[] a = in.readString().toCharArray();
		int cnt = 1;
		ArrayList<Integer> arr = new ArrayList<Integer>();
		for(int i = 1; i <= n; ++i) {
			if(i == n || a[i-1] != a[i]) {
				arr.add(cnt);
				cnt = 1;
			}
			else {
				cnt++;
			}
		}
		long not = n;
		for(int i = 0; i < arr.size(); ++i) {
			if(i-1 >= 0)
				not += arr.get(i-1);
			if(i+1 < arr.size())
				not += arr.get(i+1);
		}
		long ans = (long)n * (n+1) / 2;
		ans -= not;
		ans += arr.size() - 1;
		System.out.println(ans);
		
		out.close();
	}
	
	static int incr(int[] arr, int n, int i, int k, int prev, int max) {
		int num = prev + 1;
		while(i < n && k > 0) {
			if(num > max)
				return -1;
			arr[i] = num;
			i++; num++; k--;
		}
		return k == 0 ? i : -1;
	}
	
	static int mult(int[] arr, int n, int i, int k, int prev, int max) {
		int num = prev * 2;
		while(i < n && k > 0) {
			if(num > max)
				return -1;
			arr[i] = num;
			i++; num *= 2; k--;
		}
		return k == 0 ? i : -1;
	}
	
	
	static boolean inside(int i, int j, int n, int m) {
		return i >= 0 && i < n && j >= 0 && j < m;
	}
	
	
	static long pow(long a, long n, long mod) {
		if(n == 0)
			return 1;
		if(n % 2 == 1)
			return a * pow(a, n-1, mod) % mod;
		long x = pow(a, n / 2, mod);
		return x * x % mod;
	}
	
	
	static class SegmentTree {
		int n;
		char[] a;
		int[] seg;
		int DEFAULT_VALUE = 0;
		
		public SegmentTree(char[] a, int n) {
			super();
			this.a = a;
			this.n = n;
			seg = new int[n * 4 + 1];
			build(1, 0, n-1);
		}
		
		private int build(int node, int i, int j) {
			if(i == j) {
				int x = a[i] - 'a';
				return seg[node] = (1<<x);
			}
			int first = build(node * 2, i, (i+j) / 2);
			int second = build(node * 2 + 1, (i+j) / 2 + 1, j);
			return seg[node] = combine(first, second);
		}
		
		int update(int k, char value) {
			return update(1, 0, n-1, k, value);
		}
		
		private int update(int node, int i, int j, int k, char value) {
			if(k < i || k > j)
				return seg[node];
			if(i == j && j == k) {
				a[k] = value;
				int x = a[i] - 'a';
				return seg[node] = (1<<x);
			}
			int m = (i + j) / 2;
			int first = update(node * 2, i, m, k, value);
			int second = update(node * 2 + 1, m + 1, j, k, value);
			return seg[node] = combine(first, second);
		}
		
		int query(int l, int r) {
			return query(1, 0, n-1, l, r);
		}
		
		private int query(int node, int i, int j, int l, int r) {
			if(l <= i && j <= r)
				return seg[node];
			if(j < l || i > r)
				return DEFAULT_VALUE;
			int m = (i + j) / 2;
			int first = query(node * 2, i, m, l, r);
			int second = query(node * 2 + 1, m+1, j, l, r);
			return combine(first, second);
		}
 
		private int combine(int a, int b) {
			return a | b;
		}
	}
	
	static class DisjointSet {
		int n;
		int[] g;
		int[] h;
		public DisjointSet(int n) {
			super();
			this.n = n;
			g = new int[n];
			h = new int[n];
			for(int i = 0; i < n; ++i) {
				g[i] = i;
				h[i] = 1;
			}
		}
		int find(int x) {
			if(g[x] == x)
				return x;
			return g[x] = find(g[x]);
		}
		void union(int x, int y) {
			x = find(x); y = find(y);
			if(x == y)
				return;
			if(h[x] >= h[y]) {
				g[y] = x;
				if(h[x] == h[y])
					h[x]++;
			}
			else {
				g[x] = y;
			}
		}
	}
	
	
	static int[] getPi(char[] a) {
		int m = a.length;
		int j = 0;
		int[] pi = new int[m];
		for(int i = 1; i < m; ++i) {
			while(j > 0 && a[i] != a[j])
				j = pi[j-1];
			if(a[i] == a[j]) {
				pi[i] = j + 1;
				j++;
			}
		}
		return pi;
	}
	
	static long lcm(long a, long b) {
		return a * b / gcd(a, b);
	}
	
	static boolean nextPermutation(int[] a) {
		for(int i = a.length - 2; i >= 0; --i) {
			if(a[i] < a[i+1]) {
				for(int j = a.length - 1; ; --j) {
					if(a[i] < a[j]) {
						int t = a[i];
						a[i] = a[j];
						a[j] = t;
						for(i++, j = a.length - 1; i < j; ++i, --j) {
							t = a[i];
							a[i] = a[j];
							a[j] = t;
						}
						return true;
					}
				}
			}
		}
		return false;
	}
	
	
	static void shuffle(int[] a) {
		Random r = new Random();
		for(int i = a.length - 1; i > 0; --i) {
			int si = r.nextInt(i);
			int t = a[si];
			a[si] = a[i];
			a[i] = t;
		}
	}
	
	static void shuffle(long[] a) {
		Random r = new Random();
		for(int i = a.length - 1; i > 0; --i) {
			int si = r.nextInt(i);
			long t = a[si];
			a[si] = a[i];
			a[i] = t;
		}
	}
	
	static int lower_bound(int[] a, int n, int k) {
		int s = 0;
		int e = n;
		int m;
		while (e - s > 0) {
			m = (s + e) / 2;
			if (a[m] < k)
				s = m + 1;
			else
				e = m;
		}
		return e;
	}
	static int lower_bound(long[] a, int n, long k) {
		int s = 0;
		int e = n;
		int m;
		while (e - s > 0) {
			m = (s + e) / 2;
			if (a[m] < k)
				s = m + 1;
			else
				e = m;
		}
		return e;
	}
	
	static int gcd(int a, int b) {
		return b == 0 ? a : gcd(b, a % b);
	}
	static long gcd(long a, long b) {
		return b == 0 ? a : gcd(b, a % b);
	}
	
	static class Pair implements Comparable<Pair> {
		int first, second;
 
		public Pair(int first, int second) {
			super();
			this.first = first;
			this.second = second;
		}
 
		@Override
		public int compareTo(Pair o) {
			return this.first != o.first ? this.first - o.first : this.second - o.second;
		}
		
//		@Override
//		public int compareTo(Pair o) {
//			return this.first != o.first ? o.first - this.first : o.second - this.second;
//		}
 
		@Override
		public int hashCode() {
			final int prime = 31;
			int result = 1;
			result = prime * result + first;
			result = prime * result + second;
			return result;
		}
 
		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			Pair other = (Pair) obj;
			if (first != other.first)
				return false;
			if (second != other.second)
				return false;
			return true;
		}
	}
}
 
 
 
class InputReader {
 
	private final InputStream stream;
	private final byte[] buf = new byte[8192];
	private int curChar, snumChars;
 
	public InputReader(InputStream st) {
		this.stream = st;
	}
 
	public int read() {
		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 = read();
		while (isSpaceChar(c)) {
			c = read();
		}
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		int res = 0;
		do {
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}
 
	public long nextLong() {
		int c = read();
		while (isSpaceChar(c)) {
			c = read();
		}
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		long res = 0;
		do {
			res *= 10;
			res += c - '0';
			c = read();
		} 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 = read();
		while (isSpaceChar(c)) {
			c = read();
		}
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isSpaceChar(c));
		return res.toString();
	}
 
	public String nextLine() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isEndOfLine(c));
		return res.toString();
	}
 
	public boolean isSpaceChar(int c) {
		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	}
 
	private boolean isEndOfLine(int c) {
		return c == '\n' || c == '\r' || c == -1;
	}
 
}