{"raw_statement":[{"iden":"problem statement","content":"Snuke has an integer sequence, $a$, of length $N$. The $i$\\-th element of $a$ ($1$\\-indexed) is $a_{i}$.\nHe can perform the following operation any number of times:\n\n*   Operation: Choose integers $x$ and $y$ between $1$ and $N$ (inclusive), and add $a_x$ to $a_y$.\n\nHe would like to perform this operation between $0$ and $2N$ times (inclusive) so that $a$ satisfies the condition below. Show one such sequence of operations. It can be proved that such a sequence of operations always exists under the constraints in this problem.\n\n*   Condition: $a_1 \\leq a_2 \\leq ... \\leq a_{N}$"},{"iden":"constraints","content":"*   $2 \\leq N \\leq 50$\n*   $-10^{6} \\leq a_i \\leq 10^{6}$\n*   All input values are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$\n$a_1$ $a_2$ $...$ $a_{N}$"},{"iden":"sample input 1","content":"3\n-2 5 -1"},{"iden":"sample output 1","content":"2\n2 3\n3 3\n\n*   After the first operation, $a = (-2,5,4)$.\n*   After the second operation, $a = (-2,5,8)$, and the condition is now satisfied."},{"iden":"sample input 2","content":"2\n-1 -3"},{"iden":"sample output 2","content":"1\n2 1\n\n*   After the first operation, $a = (-4,-3)$ and the condition is now satisfied."},{"iden":"sample input 3","content":"5\n0 0 0 0 0"},{"iden":"sample output 3","content":"0\n\n*   The condition is satisfied already in the beginning."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}