import java.util.Arrays;

public class Solution {
    public static int permCheck(int[] a) {
        int[] sorted = a.clone();
        Arrays.sort(sorted);

        for (int k = 0; k < sorted.length - 1; k++) {
            if (sorted[k] != k + 1) {
                return 0;
            }
        }

        return 1;
    }
}