Neither, the chicken evolved from something over millions of years which may have even produced asexually.
If it grew from some form of unicellular organisms to multicellular organisms it probably evolved into being able to sexually reproduce.
As the ancestor evolved it's reproductive trait slowly evolved into producing a shell made of calcium carbonate. Humans have similar "eggs"
in which we are in the womb, similarly the chicken may have been a ancestor of human ancestor's which is a result of divergent evolution.
Therefore I guess in scientific terms neither came first, it was the ancestor of the chicken.
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