John wrote a 3-digits number on a piece of a paper and asked Peter to guess it. Peter asked:"Is the number 173 ?".John replied:"One of the digits is correct, the position of that difiy is also correct". Peter asked again:"Is the number 123 ?". Two digits are correct, but the position of those digits are wrong." Peter asked again:"Is the number 324 ?". All three are correct , but the digits are all in the wrong places." What is the number written by John ?
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