17 lines
340 B
Python
17 lines
340 B
Python
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def main():
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nb = input("")
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poss = ["144", "14", "1"]
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while nb != "":
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ok = False
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for i in poss:
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if nb.startswith(i):
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nb = nb[len(i):]
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ok = True
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break
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if not ok:
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print("NO")
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return
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print("YES")
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main()
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