#include <bits/stdc++.h>
# define endl            '\n'
# define clr(x,a)        memset(x,a,sizeof(x))
# define PI              3.14159265358979323846
# define vi              vector<int>
# define fo(i,n)         for(int i=1;i<=n;i++)
# define all(a)          a.begin(), a.end()
# define deb(x)          cout<<#x<<"=="<<x<<endl;
# define pb              push_back
# define sc              scanf
# define pr              printf
# define tc              int t; cin>>t; while(t--)
# define rev(s)          reverse(s.begin(),s.end())
# define linija          cout<<"____________\n";

using namespace std;
typedef long long ll;

const int mxN=100005, mod=1e9+7;
int n, b[mxN], p, a[mxN], br;
/*
10 2
0 1 1 2 2 2 2 2 2 2
*/
int suma[mxN];

int main(){
   freopen("notdecreasing.in", "r", stdin);
   freopen("notdecreasing.out", "w", stdout);
   cin>>n>>p;
   for(int i=1; i<=n; i++) sc("%d", &b[i]);

   for(int i=1; i<=n; i++){
      if(b[i]==b[i-1] or (b[i]==(b[i-1]+1)) );
      else{
         cout<<-1<<endl;
         return 0;
      }
   }
   int tre=p;
   for(int i=1; i<=n; i++){
      if(b[i]==b[i-1]){
         a[i]=tre;
         tre--;
         if(tre==1) tre=p;
      }
      else a[i]=1;
   }

   int jed=0, dva=0;
   for(int i=1; i<=n; i++){
      if(a[i]==1) jed++;
      if(a[i]==2) dva++;
      int x;
      if(dva<jed) x=dva;
      else x=jed;
      if( b[i]!=x ){
         cout<<-1<<endl;
         return 0;
      }
   }

   for(int i=1; i<=n; i++) pr("%d ", a[i]);
   cout<<endl;
	return 0;
}