#include <bits/stdc++.h>
using namespace std;

int n, m, b[105], a[10000000];
int main(){
    cin >> n >> m;
    for(int i = 0; i < m; ++i){
        cin >> b[i];
    }
    for(int i = 0; i < m; ++i){
        for(int j = b[i] - 1; j < n; ++j){
            if(a[j] == 0){
                a[j] = b[i];
            }
        }
    }
    for(int i = 0; i < n; ++i){
        cout << a[i] << " ";
    }
    return 0;
}