#include <bits/stdc++.h>
using namespace std;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, k;
cin >> n >> k;
stack<int> stk;
for (int i = 0; i < n; i++) {
int x;
cin >> x;
int prev = -1;
while (!stk.empty() && stk.top() < x) {
if (prev == -1)
prev = stk.top();
else {
for (int idx = prev; idx < stk.top(); idx++)
cout << idx << ' ';
prev = stk.top() + 1;
}
stk.pop();
}
if (prev != -1) {
for (int idx = prev; idx < x; idx++)
cout << idx << ' ';
int tx = x;
while (!stk.empty() && stk.top() == tx) {
stk.pop();
tx++;
}
stk.push(tx);
}
cout << x << ' ';
while (!stk.empty() && stk.top() == x) {
stk.pop();
x++;
}
stk.push(x);
}
int prev = -1;
while (!stk.empty()) {
if (prev == -1)
prev = stk.top();
else {
for (int idx = prev; idx < stk.top(); idx++)
cout << idx << ' ';
prev = stk.top() + 1;
}
stk.pop();
}
for (int idx = prev; idx < 30; idx++)
cout << idx << ' ';
}
