The following code attempts to implement the peak-valley approach but contains a subtle bug. Identify the line causing incorrect profit calculation.

The following code attempts to implement the peak-valley approach but contains a subtle bug. Identify the line causing incorrect profit calculation.

def maxProfit(prices):
    i = 0
    profit = 0
    n = len(prices)
    while i < n - 1:
        while i < n - 1 and prices[i] > prices[i + 1]:
            i += 1
        valley = prices[i]
        while i < n - 1 and prices[i] < prices[i + 1]:
            i += 1
        peak = prices[i]
        profit += peak - valley
    return profit