def isSquare(a):
    for i in range(int(a**0.5)+2):
        if i**2 == a:
            return True

    return False



if __name__ == '__main__':
    tempo = input()
    s = input()
    s += 'e'
    a = [0]
    c = 1
    for i in range(0, len(s)-1):
        if s[i] == s[i+1]:
            c += 1
        else:
            a.append(c)
            c = 1 
    a.append(0)

    counter = 0
    for i in range(1, len(a)-1):
        if isSquare(a[i]):
            k = a[i-1] + a[i+1]
            ob = 4*a[i] + 4
            counter += k-ob+1 if k >= ob else 0
        n = 1
        while n**2 < a[i]:
            if 4*n+4 <= a[i-1]:
                counter += 1
            if 4*n+4 <= a[i+1]:
                counter += 1
            n += 1

    print(counter)