#include <stdio.h>


int main(){
    int n,d[1000],min,temp,j;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d",&d[i]);
    }
    scanf("%d",&min);
    for(int i=1;i<n;i++){
        if(d[i]<d[i-1]){
            temp =d[i];
            for(j=i-1;j>=0&&d[j]>temp;j--){
                d[j+1] = d[j];
            }
            d[j+1] = temp;
        }
    }
    int count=1,re;
    for(int i=1;count<min;i++){
        if(d[i]>d[i-1]){
            re = d[i];
            count++;
        }
    }
    printf("%d",re);
    return 0;
}