// Task description
// This is a demo task.

// Write a function:

// function solution(A);

// that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.

// For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.

// Given A = [1, 2, 3], the function should return 4.

// Given A = [−1, −3], the function should return 1.

// Assume that:

// N is an integer within the range [1..100,000];
// each element of array A is an integer within the range [−1,000,000..1,000,000].
// Complexity:

// expected worst-case time complexity is O(N);
// expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).
// Elements of input arrays can be modified.

var result;

function getAnswer(A, min, max) {
    if (min < 0) {
        if (max < 0) {
            return 1;    
        } else {
            result = 1;
            if (A.indexOf(result) > -1) {
                return getAnswer(A, result + 1, max); 
            } else {
                return result;  
            }
        }
    } else {
        result = min;
        if (A.indexOf(result) > -1) {
            return getAnswer(A, min + 1, max); 
        } else {
            return result;  
        }
    }
}


function solution(A) {
    // write your code in JavaScript (Node.js 6.4.0)
    var min, max = 0;
    
    min = Math.min.apply(null, A);
    max = Math.max.apply(null, A);
    
    return getAnswer(A, min, max)
}