{"raw_statement":[{"iden":"problem statement","content":"$N$ players numbered $1$ through $N$ will participate in a round-robin tournament.  \nSpecifically, for every pair $(i,j) (1\\leq i \\lt j \\leq N)$, Player $i$ and Player $j$ play a match against each other once, for a total of $\\frac{N(N-1)}{2}$ matches.  \nIn every match, one of the players will be a winner and the other will be a loser; there is no draw.\n$M$ matches have already ended. In the $i$\\-th match, Player $W_i$ won Player $L_i$.\nList all the players who may become the unique winner after the round-robin tournament is completed.  \nA player is said to be the unique winner if the number of the player's wins is strictly greater than that of any other player."},{"iden":"constraints","content":"*   $2\\leq N \\leq 50$\n*   $0\\leq M \\leq \\frac{N(N-1)}{2}$\n*   $1\\leq W_i,L_i\\leq N$\n*   $W_i \\neq L_i$\n*   If $i\\neq j$, then $(W_i,L_i) \\neq (W_j,L_j)$.\n*   $(W_i,L_i) \\neq (L_j,W_j)$\n*   All values in input are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$ $M$\n$W_1$ $L_1$\n$W_2$ $L_2$\n$\\vdots$\n$W_M$ $L_M$"},{"iden":"sample input 1","content":"4 2\n2 1\n2 3"},{"iden":"sample output 1","content":"2 4\n\nPlayers $2$ and $4$ may become the unique winner, while Players $1$ and $3$ cannot.  \nNote that output like `4 2` is considered to be incorrect."},{"iden":"sample input 2","content":"3 3\n1 2\n2 3\n3 1"},{"iden":"sample output 2","content":"It is possible that no player can become the unique winner."},{"iden":"sample input 3","content":"7 9\n6 5\n1 2\n3 4\n5 3\n6 2\n1 5\n3 2\n6 4\n1 4"},{"iden":"sample output 3","content":"1 3 6 7"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}