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

vector<int> a;
int n, m, k;

int main() {
    cin >> n >> m;

    a.assign(m+2, 0);

    for(int i = 1; i <= m; i++) {
        cin >> a[i];
    }
    a[0] = a[1] - 2;
    a[m+1] = a[m] + 2;

    for(int i = m-1; i >= 0; i--) {
        if(a[i] < a[i+1]-1) {
            //cout << i << "asdasd\n";
            vector<int> b(n+1);
            for(int j = 0; j <= i+1; j++) {
                if(j<=i) b[j] = a[j];
                else if (j==i+1 && (i != 0 || a[1] != 1)) b[j] = a[j]-1;
                else if (i == 0 && a[1] == 1) b[j] = n-m+1;
            }
            int now = n;
            for(int j = m; j > 1+i; j--) {
                b[j] = now;
                now--;
            }

            for(int j = 1; j <= m; j++) {
                cout << b[j] << ' ';
            }
            cout << endl;
            i = -10;
        }
    }

    if (a[m] != n) {
        for(int j = 1; j < m; j++) {
            cout << a[j] << ' ';
        }
        cout << a[m]+1;
        return 0;
    }

    for(int i = m-1; i >= 1; i--) {
        if(a[i] < a[i+1]-1) {
            //cout << i << "asdasd\n";
            vector<int> b(n+1);

            for(int j = 0; j <= i; j++) {
                if(j<i) b[j] = a[j];
                else if (j==i) b[j] = a[j]+1;
            }
            int now = b[i] + 1;
            for(int j = i+1; j <= m; j++) {
                b[j] = now;
                now++;
            }

            for(int j = 1; j <= m; j++) {
                cout << b[j] << ' ';
            }
            cout << endl;
            return 0;
        }
    }
    for(int i = 1; i <= m; i++) {
        cout << i << ' ';
    }
}