Smaller than the element(codechef).cpp

#include<bits/stdc++.h>
#define speed ios_base::sync_with_stdio(false)
#define boost cin.tie(NULL)
#define booster cout.tie(NULL)
#define endl "\n"
typedef long long int lld;

#define F(a,n) for(int i=0;i<n;i++){cin>>a[i];}
#define F1(a,n) for(int i=1;i<=n;i++){cin>>a[i];}
#define P(a,n) for(int i=0;i<n;i++){cout<<a[i]<<' ';}cout<<endl;
#define P1(a,n) for(int i=1;i<=n;i++){cout<<a[i]<<' ';}cout<<endl;
#define NF(a,n,m) for(int i=0;i<n;i++){for(int j=0;j<m;j++){cin>>a[i][j];}}
#define NF1(a,n,m) for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){cin>>a[i][j];}}
#define PNF(a,n,m) for(int i=0;i<n;i++){for(int j=0;j<m;j++){cout<<a[i][j]<<' ';}cout<<endl;}cout<<endl;
#define PNF1(a,n,m) for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){cout<<a[i][j]<<' ';}cout<<endl;}cout<<endl;

using namespace std;

int main(){
	
	lld N;
	cin>>N;
	
	lld ar[N];
	F(ar,N);
	
	set<lld> st;
	
	for(lld i=0;i<N;i++){
		
		auto itr = st.lower_bound(ar[i]);
		
		if(itr == st.begin())
			cout<<"-1"<<endl;
		else {
			itr--;
			cout<<(*itr)<<endl;
		}
			
		st.insert(ar[i]);
			
	}
	
	return 0;
	
}