var twoSum = function(numbers, target) {
    var hash = {},
        a, b;

    for (var i = 0; i < numbers.length; i++) {
        if (hash.hasOwnProperty(numbers[i])) {
            var index = hash[numbers[i]];
            a = index;
            b = i;
            break;
        } else {
            hash[target - numbers[i]] = i;
        }
    }

    return [a + 1, b + 1];
};