function solve (arr, num) {


      let sum = 0;

      let arr2 = [];


        for (let i = 0; i < arr.length; i++) {


          for (let j = 0; j < arr.length; j++) {

          sum = arr[i] + arr[j];

            if (arr.indexOf(arr[i]) === arr.indexOf(arr[j])) {

              continue;

            }

          const check = arr2.some(par => par === arr[i] || par === arr[j]);

          if (sum === num && check === false) {


            console.log(`${arr[i]} ${arr[j]}`);

            arr2.push(arr[i], arr[j]);

            break;

        }

      }



    }

  }



    console.log(solve([1, 2, 3, 4, 5, 6], 6));