How many times did the cock crow? Bible Contradictions

This Bible contradiction is from the Infidels.org.

Verses

Mark 14:72 View context

And the second time the cock crew. And Peter called to mind the word that Jesus said unto him, Before the cock crow twice, thou shalt deny me thrice. And when he thought thereon, he wept.

Matthew 26:74 View context

Then began he to curse and to swear, [saying], I know not the man. And immediately the cock crew.

Matthew 26:75 View context

And Peter remembered the word of Jesus, which said unto him, Before the cock crow, thou shalt deny me thrice. And he went out, and wept bitterly.

Luke 22:60 View context

And Peter said, Man, I know not what thou sayest. And immediately, while he yet spake, the cock crew.

Luke 22:61 View context

And the Lord turned, and looked upon Peter. And Peter remembered the word of the Lord, how he had said unto him, Before the cock crow, thou shalt deny me thrice.

John 13:38 View context

Jesus answered him, Wilt thou lay down thy life for my sake? Verily, verily, I say unto thee, The cock shall not crow, till thou hast denied me thrice.