{"problem":{"name":"First Second","description":{"content":"Limak can repeatedly remove one of the first two characters of a string, for example $abcxyx \\rightarrow acxyx \\rightarrow cxyx \\rightarrow cyx$. You are given $N$ different strings $S_1, S_2, \\ldots,","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":3000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"agc047_b"},"statements":[{"statement_type":"Markdown","content":"Limak can repeatedly remove one of the first two characters of a string, for example $abcxyx \\rightarrow acxyx \\rightarrow cxyx \\rightarrow cyx$.\nYou are given $N$ different strings $S_1, S_2, \\ldots, S_N$. Among $N \\cdot (N-1) / 2$ pairs $(S_i, S_j)$, in how many pairs could Limak obtain one string from the other?\n\n## Constraints\n\n*   $2 \\leq N \\leq 200\\,000$\n*   $S_i$ consists of lowercase English letters `a`\\-`z`.\n*   $S_i \\neq S_j$\n*   $1 \\leq |S_i|$\n*   $|S_1| + |S_2| + \\ldots + |S_N| \\leq 10^6$\n\n## Input\n\nInput is given from Standard Input in the following format.\n\n$N$\n$S_1$\n$S_2$\n$\\vdots$\n$S_N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"agc047_b","tags":[],"sample_group":[["3\nabcxyx\ncyx\nabc","1\n\nThe only good pair is $(abcxyx, cyx)$."],["6\nb\na\nabc\nc\nd\nab","5\n\nThere are five good pairs: $(b, abc)$, $(a, abc)$, $(abc, c)$, $(b, ab)$, $(a, ab)$."]],"created_at":"2026-03-03 11:01:14"}}