def longest_consec(strarr, k):
    n = len(strarr)
    if k > n or k <=0 or n==0:
        return ""
    longest = index = 0
    for i in range(n - k+1):
        length = sum([len(s) for s in strarr[i: i + k]])
        if length > longest:
            longest = length
            index = i

    return ''.join(strarr[index: index + k])