#include<cstdio>

#include<cstring>

#include<algorithm>

#define N 4005

int n,i,j,x,y,len[N],b[N],f[2][N],cnt[2],q[N],t;char a[N][N];

inline bool cmp(int x,int y){return len[x]<len[y];}

inline bool check(int x,int y){

  if(len[x]>len[y])return 0;

  for(int i=j=0;i<len[x];i++){

    while(j<len[y]&&a[x][i]!=a[y][j])j++;

    if(j==len[y])return 0;

    j++;

  }

  return 1;

}

int main(){

  scanf("%d",&n);

  for(i=0;i<=n;i++){

    scanf("%s",a[i]);

    len[i]=strlen(a[i]);

    b[i]=i;

    if(!check(i,0))return puts("impossible"),0;

  }

  len[0]=0;

  std::sort(b+1,b+n+1,cmp);

  for(i=1;i<=n;i++){

    x=check(f[0][cnt[0]],b[i]);

    y=check(f[1][cnt[1]],b[i]);

    if(!x&&!y)return puts("impossible"),0;

    if(x&&!y){

      f[0][++cnt[0]]=b[i];

      for(j=1;j<=t;j++)f[1][++cnt[1]]=q[j];

      t=0;

    }

    if(!x&&y){

      f[1][++cnt[1]]=b[i];

      for(j=1;j<=t;j++)f[0][++cnt[0]]=q[j];

      t=0;

    }

    if(x&&y){

      if(check(q[t],b[i]))q[++t]=b[i];

      else{

        f[0][++cnt[0]]=b[i];

        for(j=1;j<=t;j++)f[1][++cnt[1]]=q[j];

        t=0;

      }

    }

  }

  for(j=1;j<=t;j++)f[1][++cnt[1]]=q[j];

  printf("%d %d\n",cnt[0],cnt[1]);

  for(i=1;i<=cnt[0];i++)puts(a[f[0][i]]);

  for(i=1;i<=cnt[1];i++)puts(a[f[1][i]]);

  return 0;

}