import math

num_letters = int(input())
letters = input()

def is_perfect_sq(x):
    return abs(math.modf(math.sqrt(x))[0]) < 0.00001

i=3
combinations = 0
while i**2 <= num_letters:
    count_x = 0
    count_0 = 0
    for j in range(i**2):
        if letters[j] == "X":
            count_x += 1
        else:
            count_0 += 1
    
    j = 0
    while i**2 + j <= num_letters:
        should_continue = True
        val = None
        val2 = None
        if is_perfect_sq(count_x):
            val = count_x
            val2 = count_0
        elif is_perfect_sq(count_0):
            val = count_0
            val2 = count_x
        else:
            should_continue = False
        if should_continue:
            if (4*math.sqrt(val)+4==val2):
                combinations += 1
            if (4*math.sqrt(val2)+4==val):
                combinations += 1
        j += 1
        if i**2 + j > num_letters:
            break
        if letters[j-1] == "X":
            count_x -= 1
        else:
            count_0 -= 1
        if letters[i**2+j-1] == "X":
            count_x += 1
        else:
            count_0 += 1
    i+=1

print(combinations)