#include <bits/stdc++.h>

using namespace std;

struct music{
    string nome;
    struct music *prox;
};

struct playlist{
    string nome;
    struct playlist *next;

    struct music *prox;
};

music *moveVmusic(music *head, string val){
    music *cursor = head;
    while(cursor && cursor->prox){
        if(cursor->prox && cursor->prox->nome == val){
            break;
        }
        cursor = cursor->prox;
    }
    return cursor;
}

playlist *criarSent(playlist *cursor){
    music *_new = new music;
    _new->prox = cursor->prox;
    _new->nome = "SentinelaMusical";
    cursor->prox = _new;
    return cursor;
}


playlist *insertPlay(playlist *cursor, string val){
    playlist *_new = new playlist;
    _new->nome = val;
    _new->next = cursor->next;
    cursor->next = _new;
    return cursor;
}

playlist *addPlay(playlist *cursor, string val){
    while(cursor && cursor->next){
        cursor = cursor->next;
    }
    cursor = insertPlay(cursor,val);
    cursor->next->next = NULL;
    cursor->next = criarSent(cursor->next);
    return cursor;
}

music *insertMusic(music *cursor, string val){
    music *_new = new music;
    _new->nome = val;
    _new->prox = cursor->prox;
    cursor->prox = _new;
    return cursor;
}

music *addMusic(music *cursor, string val){
    while(cursor && cursor->prox){
        cursor = cursor->prox;
    }
    cursor = insertMusic(cursor,val);
    cursor->prox->prox = NULL;
    return cursor;
}

music *removMusic(music *cursor){
    music *p = (music *)malloc(sizeof(music));
    p = cursor->prox;
    cursor->prox = p->prox;
    free(p);
    return cursor;
}

int main(){

    int i, j = 0, k = 0, t =0;
    int n;
    int tamanho = 0;
    int rep = -1000;

    string fun;
    string play;
    string song;
    string song2;

    playlist *head = NULL;
    playlist *cur = NULL;
    playlist sent;

    music *aux = NULL;
    music *curM = NULL;

    head = &sent;
    cur = head;
    cur->next = NULL;

    string f[100000];

    cin >> n;

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

        cin >> fun;

        if(fun[0] == 'A' && fun[1] == 'D' && fun[2] == 'D'){
            k = 0;
            j = 0;
            cin >> play;
            cur = head;
            while(cur && cur->next){
                if(cur->next->nome == play){
                    k = 1;
                    break;
                }else{
                    cur = cur->next;
                }
            }
            if(k != 1){
                cur = addPlay(cur,play);
            }

            curM = cur->next->prox;
            cin >> song;
            curM = addMusic(curM,song);
        }else if(fun[0] == 'D' && fun[1] == 'E' && fun[2] == 'L'){
            k = 0;
            j = 0;
            cin >> play;
            cur = head;
            curM = cur->next->prox;
            while(cur && cur->next){
                if(cur->next->nome == play){
                    k = 1;
                    break;
                }else{
                    cur = cur->next;
                }
            }

            cin >> song;

            if(k == 1){
                curM = cur->next->prox;
                curM = moveVmusic(curM,song);
                if(curM && curM->prox){
                    curM = removMusic(curM);
                }
            }
        }else if(fun[0] == 'S' && fun[1] == 'W' && fun[2] == 'P'){
            k = 0;
            j = 0;
            t = 0;
            cin >> play;
            cur = head;
            curM = cur->next->prox;
            while(cur && cur->next){
                if(cur->next->nome == play){
                    k = 1;
                    break;
                }else{
                    cur = cur->next;
                }
            }
            cin >> song;
            cin >> song2;
            if(k == 1){
                curM = cur->next->prox;
                while(curM && curM->prox){
                    if(curM->prox->nome == song){
                        j = 1;
                        break;
                    }else{
                        curM = curM->prox;
                    }
                }
                aux = curM;
                curM = cur->next->prox;
                while(curM && curM->prox){
                    if(curM->prox->nome == song2){
                        t = 1;
                        break;
                    }else{
                        curM = curM->prox;
                    }
                }
                if(j == 1 && t == 1){
                    curM->prox->nome == song;
                    aux->prox->nome == song2;
                }
            }
        }else if(fun[0] == 'P' && fun[1] == 'L' && fun[2] == 'S'){
            cin >> song;
            if(tamanho == 0){
                rep = 0;
            }
            f[tamanho++] == song;
        }else if(fun[0] == 'P' && fun[1] == 'L' && fun[2] == 'P'){
            k = 0;
            j = 0;
            tamanho = 0;
            cin >> play;
            cur = head;
            curM = cur->next->prox;
            while(cur && cur->next){
                if(cur->next->nome == play){
                    k = 1;
                    break;
                }else{
                    cur = cur->next;
                }
            }
            if(k == 1){
                curM = cur->next->prox;
                for(j=0;curM->prox;j++){
                    f[tamanho++] = curM->prox->nome;
                    curM = curM->prox;
                }
            }
            rep = 0;
            if(tamanho == 0){
                rep = -1000;
            }
        }else if(fun[0] == 'N' && fun[1] == 'X' && fun[2] == 'T'){
            if(rep != -1000){
                rep = rep + 1;
            }
        }else if(fun[0] == 'P' && fun[1] == 'R' && fun[2] == 'V'){
            if(rep != -1000){
                rep = rep - 1;
            }
        }else if(fun[0] == 'C' && fun[1] == 'L' && fun[2] == 'R'){
            tamanho = 0;
            rep = -1000;
        }else if(fun[0] == 'I' && fun[1] == 'N' && fun[2] == 'F'){
            if(rep == -1000 || rep >= tamanho || rep < 0){
                cout << "UNKNOWN" << endl;
            }else{
                cout << f[rep] << endl;
            }
        }

     //  printf("\n");
      //  verplaylists(head);
      //  printf("\n");
      //  verfila(f,tamanho);
     //   printf("\n");
    }


    return 0;

}