#include <fstream>

using namespace std;

int main()
{
  int c1[300],c2[300];
  int t,ok,x,i,j,m,n;
  fstream fi("pavare2.in", ios::in);
  fstream fo("pavare2.out", ios::out);
  fi >> n >> m ;
  for(i=1;i<=n;n++)
    {
      ok=0;
    for(j=1;j<=m;j++)
     if (c1[j]==0)
       {
                fi>>x; ok=1;
                for(t=j+1;j<=j+x-1;j++) {c1[t]=x; c2[t]=1; }
                if (x<0)  {
                          x=-x;
                          c1[j]=x;
                          c2[j]=c1[j]-1;
                          } fo <<x<<" ";
       }
       else
       {
        x=c1[j];
        c2[j]=c2[j]-1;
        if (c2[j]==0) c1[j]=0;
        fo<<x<<" ";
       }
      if (ok==0) fi>>x;
     fo<<endl; }
   fo.close();
   return 0;
}