// Find the odd int
// Given an array, find the int that appears an odd number of times.

// There will always be only one integer that appears an odd number of time

function findOdd(A) {
  //happy coding!
  const count = A.reduce((count, index) => {
    if (count.hasOwnProperty(index)) {
      count[index] += 1
    } else {
      count[index] = 1
    }
    return count;
  }, {});
  var oddInteger
  for (var property in count) {
    if (count[property] % 2 != 0) {
      oddInteger = property;
    }
  }


  return Number(oddInteger);
}

findOdd([20, 1, -1, 2, -2, 3, 3, 5, 5, 1, 2, 4, 20, 4, -1, -2, 5])