s = "abcbcd"
alph = "abcdefghijklmnopqrstuvwxyz"
temp = 0
list = ""
fin = []
for i in range(len(s)):

    if s[i] in alph:
        fin.append(list)
        list = list + s[i]
        prev = alph.index(s[i])
        if prev >= temp:
            temp = prev
        else:
            temp = 0
            list = ""
            prev = alph.index(s[i])
            if prev >= temp:
                temp = prev
                list = list + s[i]
fin.append(list)
#print fin
max = 0
get = ""
for each in fin:
    if max<len(each):
        max = len(each)
        get = each

print "Longest string in alphabetical order is: "+get