{"raw_statement":[{"iden":"problem statement","content":"We have $4$ cards with an integer $1$ written on it, $4$ cards with $2$, $\\ldots$, $4$ cards with $N$, for a total of $4N$ cards.\nTakahashi shuffled these cards, removed one of them, and gave you a pile of the remaining $4N-1$ cards. The $i$\\-th card $(1 \\leq i \\leq 4N - 1)$ of the pile has an integer $A_i$ written on it.\nFind the integer written on the card removed by Takahashi."},{"iden":"constraints","content":"*   $1 \\leq N \\leq 10^5$\n*   $1 \\leq A_i \\leq N \\, (1 \\leq i \\leq 4N - 1)$\n*   For each $k \\, (1 \\leq k \\leq N)$, there are at most $4$ indices $i$ such that $A_i = k$.\n*   All values in input are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$\n$A_1$ $A_2$ $\\ldots$ $A_{4N - 1}$"},{"iden":"sample input 1","content":"3\n1 3 2 3 3 2 2 1 1 1 2"},{"iden":"sample output 1","content":"3\n\nTakahashi removed a card with $3$ written on it."},{"iden":"sample input 2","content":"1\n1 1 1"},{"iden":"sample output 2","content":"1"},{"iden":"sample input 3","content":"4\n3 2 1 1 2 4 4 4 4 3 1 3 2 1 3"},{"iden":"sample output 3","content":"2"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}