'use strict';

function getNextPositions(start) {
  var moves = [
    { x: -2, y: -1 },
    { x: -2, y: +1 },    
    { x: -1, y: -2 },    
    { x: -1, y: +2 },    
    { x: +1, y: -2 },    
    { x: +1, y: +2 },    
    { x: +2, y: -1 },    
    { x: +2, y: +1 }
  ];

  var positions = [];

  for (var i = 0; i < moves.length; i++) {
    var move = moves[i];
    var position = {};
    position.x = start.x + move.x;
    position.y = start.y + move.y;
    positions.push(position);
  }

  return positions;
}

function countMovesTo(destination, depth, cache) {
  depth = depth || 0;
  cache = cache || {};
  var result = (cache[destination.x]||{})[destination.y];

  if (result) {
    return result;
  }

  if (destination.x === 0 && destination.y === 0) {
    result = 0;
  } else if (depth > 100) {
    result = -2;
  } else {
    var minMoves = Infinity;
    var nextPositions = getNextPositions(destination);

    for (var i = 0; i < nextPositions.length; i++) {
      var nextPosition = nextPositions[i];
      var result = countMovesTo(nextPosition, depth + 1, cache);

      if (result < 0) {
        continue;
      }

      // console.log('found at moves', result);
      minMoves = Math.min(minMoves, 1 + result);
    }

    if (minMoves === Infinity) {
      result = -2
    } else {
      result = minMoves
    }
  }

  cache[destination.x] = cache[destination.x] || {};
  cache[destination.x][destination.y] = result;

  return result;
}

function solution(A, B) {
  return countMovesTo({x: A, y: B })
}

console.log(solution(4, 5));