Gym 313459B

#include<bits/stdc++.h>

using namespace std;

#define gc c=getchar()
#define r(x) read(x)
#define ll long long

template<typename T>
inline void read(T&x){
    x=0;T k=1;char gc;
    while(!isdigit(c)){if(c=='-')k=-1;gc;}
    while(isdigit(c)){x=x*10+c-'0';gc;}x*=k;
}

int cnt[10];
int pointer[10];
int a[10][10];
vector<int>tmp;

int main(){
    // freopen(".in","r",stdin);
    // freopen(".out","w",stdout);
    int n;r(n);
    for(int i=0;i<n;++i){
        r(cnt[i]);
        for(int j=0;j<cnt[i];++j){
            r(a[i][j]);
            tmp.push_back(a[i][j]);
        }
    }
    sort(tmp.begin(),tmp.end());
    for(int i=0;i<tmp.size();++i){
        for(int j=0;j<n;++j){
            if(a[j][pointer[j]]==tmp[i]){
                ++pointer[j];
                putchar('A'+j);
                break;
            }
        }
    }
    puts("");
    return 0;
}