#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int main() {
int n, m, b[105], a;
memset(b, 0, sizeof(b));
scanf("%d%d", &n, &m);
while(m--) {
scanf("%d", &a);
for(int i=a-1; i<n; i++) {
if(b[i]==0) b[i]=a;
else break;
}
}
for(int i=0; i<n; i++) printf("%d ", b[i]);
return 0;
}
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