s = list(input())
n = len(s)
S = [int(s[i]) for i in range(n)]
count = 0

def f(X):
  p = 0
  if len(X) >= 4:
    for i in range(0,len(X)-4):
      if [X[i],X[i+1],X[i+2],X[i+3]] == [1,1,0,0] or [1,0,1,0] or [0,1,0,1]or[0,0,1,1]):
        X = X[0:i+2] + X[i+3:len(X)+1]
        return(X)
      