QUESTION:int mystery(int level, int x) {
   if(level == 0) {
      return NUM;
   } else {
      return RECURSION;
   }
}
What is the result of mystery(3, 5);
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RECURSION:CALL|CALL OP TERM
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CALL:mystery(level - 1, EXP)
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EXP:TERM|EXP OP TERM
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TERM:CALL|x|1|5|-TERM
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OP:+|-|*|%|/
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