#include <bits/stdc++.h>
using namespace std;

typedef unsigned long long ULL;
const int N = 1e6 , P = 131;
ULL p[N], h[N], g[N];//前缀哈希  后缀哈希 

char s[N], t[N];//原字符串 取反字符
int n;
ULL res = 0;

/*ULL get(int l ,int r ,bool flag)
{
    if(flag)
        return h[r] - h[l-1] * P[r - l + 1];
}*/


void fun(int i)
{
    int l = 0, r = i; // r = min( i , n - i );
    while (l < r)
    {
        int mid = (l + r + 1) >> 1;
        if (h[i] - h[i - mid] * p[mid] == g[i + 1] - g[i + 1 + mid] * p[mid]) 
            l = mid;
        else r = mid - 1;
    }
    res += l; 
}
// 字符串哈希
void init()
{
    p[0] = 1;
    for(int i = 1; i <= n ; i++)
    {
        h[i] = h[i-1] * P + s[i];
        p[i] = p[i-1] * P;
    }
}

int main()
{
    cin >> n;
    scanf("%s", s + 1);

    init();

    // 取反
    for (int i = 1; i <= n; i ++) t[i] = s[i] == '1' ? '0' : '1';

    for (int i = n; i >= 1; i --) g[i] = g[i + 1] * P + t[i]; // 后缀哈希

    for (int i = 1; i < n; i ++) fun(i);

    cout << res << endl;

    return 0;
}