#include<bits/stdc++.h>
using namespace std;
constexpr int M=256*256+5;
int n,cnt,maxn,idx,tot,fa[M],val[M],pos[M],match[M],tr[M][52];
vector<int>adj[M],nxt[M],now[M];map<string,int>mp;
string str,tmp,prt[M];char cur[M];bool vis[M];
int trs1(char ch){return islower(ch)?ch-'a':ch-'A'+26;}
int trs2(int x){return x<26?x+'a':x+'A'-26;}
int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin>>n;getline(cin,str);
    for (int i=1;i<=n;i++){
        string str;getline(cin,str);str+=' ';
        maxn=idx=0;nxt[0]={0};
        auto insert=[&](auto str){ int cnt=0;
            for (int i=0;i<=maxn;i++) swap(nxt[i],now[i]),nxt[i].clear();
            for (int i=0;i<=maxn+1&&cnt<n;i++)
                for (int j=0;j<i&&cnt<n;j++) if (i-j-1<str.size())
                    for (auto &x:now[j]) if (cnt<n){
                        int ch=trs1(str[i-j-1]);
                        if (!tr[x][ch]) fa[tr[x][ch]=++idx]=x,cur[idx]=trs2(ch);
                        x=tr[x][ch];maxn=max(maxn,i);
                        if (!vis[x]) cnt++,nxt[i].emplace_back(x),vis[x]=1;
                    } 
            for (int i=0;i<=maxn;i++)
                for (auto j:nxt[i]) vis[j]=0;
        };
        for (int i=0;i<str.size();i++)
            if (str[i]==' ')
                insert(tmp),tmp="";
            else tmp+=str[i];
        for (int j=0;j<=maxn;j++)
            for (auto &x:nxt[j]){string res="";
                while (x) res+=cur[x],x=fa[x];
                reverse(res.begin(),res.end());
                if (!mp.count(res)) val[mp[res]=++tot]=j,prt[tot]=res;
                adj[mp[res]].emplace_back(i);
            }
        for (int i=0;i<=maxn;i++) now[i].clear(),nxt[i].clear();
        for (int i=0;i<=idx;i++)
			for (int j=0;j<52;j++) tr[i][j]=0;
    }
    iota(pos+1,pos+tot+1,1);
    sort(pos+1,pos+tot+1,[&](int x,int y){return val[x]<val[y];});
    for (int i=1;i<=tot;i++){
        for (int j=1;j<=tot;j++) vis[j]=0;
        auto dfs=[&](auto self,auto x)->int {
            if (vis[x]) return 0;vis[x]=1;
            for (auto y:adj[x])
                if (!match[y]||self(self,match[y]))
                    return match[y]=x,1;
            return 0;
        };
        cnt+=dfs(dfs,pos[i]);
    }
	if (cnt!=n) return puts("no solution"),0;
    for (int i=1;i<=n;i++)
        puts(prt[match[i]].c_str());
    return 0;
}