# Write a function to find the maximum sum that can be formed which has no three consecutive elements present.
def max_sum_of_three_consecutive(arr, n):
    sum = [0 for k in range(n)]
    if n >= 1:
        sum[0] = arr[0]
    if n >= 2:
        sum[1] = arr[0] + arr[1]
    if n > 2:
        sum[2] = max(sum[1], max(arr[1] + arr[2], arr[0] + arr[2]))
    for i in range(3, n):
        sum[i] = max(
            max(sum[i - 1], sum[i - 2] + arr[i]), arr[i] + arr[i - 1] + sum[i - 3]
        )
    return sum[n - 1]
