def min_avg_two_slice(a: list[int]) -> int:
    idx = 0
    min_avg = (a[0] + a[1]) / 2
    for i in range(len(a) - 1):
        cur = (a[i] + a[i + 1]) / 2
        if i + 2 < len(a):
            three = (a[i] + a[i + 1] + a[i + 2]) / 3
            cur = min(cur, three)
        if cur < min_avg:
            min_avg = cur
            idx = i

    return idx