include <bits/stdc++.h>

define ronaldo iosbase::syncwith_stdio(0);cin.tie(0);cout.tie(0);

using namespace std; int main(){

ronaldo;
long n,m;
cin>>n>>m;
int n1 = n;

priority_queue <int> gq; while(n1--){ int a;cin>>a; gq.push(a); } if(n<m){ cout<<-1<<endl; return 0; } else{ m-=1; while(m--){ gq.pop(); } cout<<gq.top()<<endl; }

}

include <bits/stdc++.h>

using namespace std; int main(){

long n,m; cin>>n>>m; int n1 = n; priority_queue <int> gq; while(n1--){ int a; cin>>a; gq.push(a); } if(n<m){ cout<<-1<<endl; return 0; } else{ m-=1; while(m--){ gq.pop(); } cout<<gq.top()<<endl; }

}

inanan inansin inanmayan inanmasin ya

include <iostream>

include <algorithm>

using namespace std; int main() { long long n,k,a,s=0; cin>>n>>k; long long x[n]; for(int i=0;i<n;i++){ cin>>x[i]; } sort(x,x+n); reverse(x,x+n);

for(int i=0;i<n;i++){
    if(i==k-1){
       a=x[i];
       s++;
       break;
    }
}
for(int i=0;i<n;i++){
if(s!=0){
    cout<<a;
    break;
}else{
    cout<<"-1";
    break;
}
}
return 0;

}