#include <bits/stdc++.h>
using namespace std;
#define Sonic ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define tests(t) int t; cin >> t; while(t--)
#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define ln cout<<endl;
#define sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define read(x) for(auto &el : x) cin >> el;
#define reads(s, n) for(int i = 0, x; i < n; ++i) {cin >> x; s.insert(x);}
#define forn(i,n) for(int i=0; i < int(n); ++i)
#define forsn(i, s, n) for (int i = s; i < n; ++i)
#define dforn(i, n) for (int i = n - 1; i >= 0; --i)
#define DBG(x) cout << #x << " = " << x << endl;
#define print(x) for(auto &el : x) {cout << el << " ";} cout<<endl;
#define lw(c, x) int(lower_bound((c).begin(), (c).end(), (x)) - (c).begin())
#define up(c, x) int(upper_bound((c).begin(), (c).end(), (x)) - (c).begin())
#define sino(b) cout<<(b ? "YES\n":"NO\n");
#define syso(x) cout<< (x) <<endl;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int,int> pii;
typedef pair<int,pii> piii;
typedef pair<ll,ll> pll;
ll gcd(ll a, ll b){while(b){a%=b; swap(a,b);} return a;} ll lcm(ll a,ll b){return a*b/gcd(a,b);}
int lg2(const int &x) { return 31-__builtin_clz(x);} // int lg2(const ll &x) {return 63-__builtin_clzll(x);}
// Para leer e imprimir .txt
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
void solve(){
int n; cin >> n;
int m; cin >> m;
set<int> s;
map<int,int> mp;
forn(i,n) {
int x; cin >> x;
s.insert(x);
mp[x]++;
}
forn(i,m) {
int x; cin >> x;
if (!sz(s)) {syso(-1)continue;}
auto it = s.lower_bound(x);
if (it == s.begin() && *it > x) {syso(-1)continue;}
if(it == s.end() || *it > x) --it;
syso(*it)
mp[*it]--;
if (!mp[*it]) s.erase(*it);
}
}
int main(){
Sonic
// tests(t)
solve();
return 0;
}
//"Quiero picha" - Sebastian Nieto 2026
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