# CCI - Problem 1.3
# URLify - Convert all spaces in a string to '%20'
# String must have enough trailing spaces to accommodate conversion

s1 = input("Enter a string: ")
s = list(s1)
true_str = s1.strip()
true_length = len(true_str)
curr = len(s1)-1
for i in range(true_length-1,0,-1):
  if (s[i]==' '):
    s[curr] = '0'
    curr -= 1
    s[curr] = '2'
    curr -= 1
    s[curr] = '%'
    curr -= 1
  else:
    s[curr] = s[i]
    curr -= 1

print("".join(s))