# Модуль 2: коэффициент корреляции Пирсона
import math

def correlation(l1, l2):
    n = min(len(l1), len(l2))
    x = l1[:n]
    y = l2[:n]

    sx = sum(x)
    sy = sum(y)

    sxx = 0
    syy = 0
    sxy = 0

    for i in range(n):
        sxx += x[i] * x[i]
        syy += y[i] * y[i]
        sxy += x[i] * y[i]

    num = n * sxy - sx * sy
    den = math.sqrt((n * sxx - sx * sx) * (n * syy - sy * sy))

    return num / den