You don't seem to know what a contradiction is either.
Those accounts are complimentary, not contradictory. There is no mutual exclusivity.
Here are the verses in question:
Mark 16:5 And entering into the sepulchre, they saw a young man sitting on the right side, clothed in a long white garment; and they were affrighted.
John 20:12 And seeth two angels in white sitting, the one at the head, and the other at the feet, where the body of Jesus had lain.
Luke 24:4 And it came to pass, as they were much perplexed thereabout, behold, two men stood by them in shining garments:
Matt 28:5 And the angel answered and said unto the women, Fear not ye: for I know that ye seek Jesus, which was crucified.
It is easily harmonized: When they entered, they saw two angels sitting, who looked like men, wearing shining garments of which at least one was white and long, then they stood up and at least one of them spoke. where is the contradiction?
You should also look into the principle of charity since it's part of a sound philosophical assessment and includes the following provision:
"We seek to understand the ideas in their most persuasive form and actively attempt to resolve contradictions. If more than one view is presented, we choose the one that appears the most cogent."