{"problem":{"name":"Brick Break","description":{"content":"We have $N$ bricks arranged in a row from left to right. The $i$\\-th brick from the left $(1 \\leq i \\leq N)$ has an integer $a_i$ written on it. Among them, you can break at most $N-1$ bricks of your ","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc148_d"},"statements":[{"statement_type":"Markdown","content":"We have $N$ bricks arranged in a row from left to right.\nThe $i$\\-th brick from the left $(1 \\leq i \\leq N)$ has an integer $a_i$ written on it.\nAmong them, you can break at most $N-1$ bricks of your choice.\nLet us say there are $K$ bricks remaining. Snuke will be satisfied if, for each integer $i$ $(1 \\leq i \\leq K)$, the $i$\\-th of those brick from the left has the integer $i$ written on it.\nFind the minimum number of bricks you need to break to satisfy Snuke's desire. If his desire is unsatisfiable, print `-1` instead.\n\n## Constraints\n\n*   All values in input are integers.\n*   $1 \\leq N \\leq 200000$\n*   $1 \\leq a_i \\leq N$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$a_1$ $a_2$ $...$ $a_N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc148_d","tags":[],"sample_group":[["3\n2 1 2","1\n\nIf we break the leftmost brick, the remaining bricks have integers $1$ and $2$ written on them from left to right, in which case Snuke will be satisfied."],["3\n2 2 2","\\-1\n\nIn this case, there is no way to break some of the bricks to satisfy Snuke's desire."],["10\n3 1 4 1 5 9 2 6 5 3","7"],["1\n1","0\n\nThere may be no need to break the bricks at all."]],"created_at":"2026-03-03 11:01:14"}}