string
res = ""
for i in range(len(s)):
n = i
while n <len(s)-1 and s[n] <= s[n+1]:
n += 1
if n+1-i > len(res):
res = s[i:n+1]
print('Longest substring in alphabetical order is: '+res)
res = ""
for i in range(len(s)):
n = i
while n <len(s)-1 and s[n] <= s[n+1]:
n += 1
if n+1-i > len(res):
res = s[i:n+1]
print('Longest substring in alphabetical order is: '+res)