gori(n)

heights = []
for i in iter(input, "0"):
    heights.append(int(i))

indexes = []
for point in range(1, len(heights) - 1):
    if heights[point - 1] < heights[point] and heights[point] > heights[point + 1]:
        indexes.append(point)

try:
    print(min(filter(lambda x : x > 0, (x-y for x in indexes for y in indexes))))
except ValueError:
    print(0)