text: function DNAStrand(dna) {
    dna = dna.toUpperCase();
    let compliments = {
      A: "T",
      T: "A",
      C: "G",
      G: "C",
    };
    let new_str = "";
    for (let i = 0; i < dna.length; i++) {
      new_str += compliments[dna[i]];
    }
    return new_str;
  }
  
  let ret = DNAStrand("AAAAA");
  console.log(ret);
  