{"problem":{"name":"Connected Checkerboard","description":{"content":"We have an $N×N$ checkerboard. From the square at the upper left corner, a square that is $i$ squares to the right and $j$ squares below is denoted as $(i, j)$. Particularly, the square at the upper l","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"relay_j"},"statements":[{"statement_type":"Markdown","content":"We have an $N×N$ checkerboard.\nFrom the square at the upper left corner, a square that is $i$ squares to the right and $j$ squares below is denoted as $(i, j)$. Particularly, the square at the upper left corner is denoted as $(0, 0)$.\nEach square $(i, j)$ such that $i+j$ is even, is colored black, and the other squares are colored white.\nWe will satisfy the following condition by painting some of the white squares:\n\n*   Any black square can be reached from square $(0, 0)$ by repeatedly moving to a black square that shares a side with the current square.\n\nAchieve the objective by painting at most $170000$ squares black.\n\n## Constraints\n\n*   $1 \\leq N \\leq 1,000$\n\n## Input\n\nThe input is given from Standard Input in the following format:\n\n$N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"relay_j","tags":[],"sample_group":[["2","1\n1 0"],["4","3\n0 1\n2 1\n2 3"]],"created_at":"2026-03-03 11:01:13"}}