Print DNA

function dnaPrint(number) {

    let str = "ATCGTTAGGG";

    let counter = 0;

    for (let i = 0; i < number; i++) {

      if (i % 4 == 0) {

        console.log(`**${str[counter % 10]}${str[(counter % 10) + 1]}**`);

      } else if (i % 4 == 1) {

        console.log(`*${str[counter % 10]}--${str[(counter % 10) + 1]}*`);

      } else if (i % 4 == 2) {

        console.log(`${str[counter % 10]}----${str[(counter % 10) + 1]}`);

      } else if (i % 4 == 3) {

        console.log(`*${str[counter % 10]}--${str[(counter % 10) + 1]}*`);

      }

      counter += 2;

    }

  }
  dnaPrint(4);