a string call happy prefix nonempty prefix suffix exclude itselfgiven string s return long happy prefix s Return string prefix exist Example 1input s leveloutput lExplanation s contain 4 prefix exclude l le lev leve suffix l el vel evel the large prefix suffix give lExample 2input s abababoutput ababexplanation abab large prefix suffix they overlap original string Constraints1 slength 105s contain lowercase english letter