const repeatNumbers = function(data) {
  // Put your solution here

  let arrstring = "";
  let value = 0;
  let count = 0;
  // let sum = 0;

  for (var i = 0; i < data.length; i++) {

    value = data[i][0];
    count = data[i][1];

    for (var j = 0; j < count; j++){

      if ( j !== (count - 1) || i === (data.length - 1)) {

        arrstring = arrstring + value

      } else {

        arrstring = arrstring + value + ','

      }

    }

  }

  return arrstring;

};

console.log(repeatNumbers([[1, 10]]));
console.log(repeatNumbers([[1, 2], [2, 3]]));
console.log(repeatNumbers([[10, 4], [34, 6], [92, 2]]));