{"problem":{"name":"Triangles","description":{"content":"Takahashi has $N$ sticks that are distinguishable from each other. The length of the $i$\\-th stick is $L_i$. He is going to form a triangle using three of these sticks. Let $a$, $b$, and $c$ be the le","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc143_d"},"statements":[{"statement_type":"Markdown","content":"Takahashi has $N$ sticks that are distinguishable from each other. The length of the $i$\\-th stick is $L_i$.\nHe is going to form a triangle using three of these sticks. Let $a$, $b$, and $c$ be the lengths of the three sticks used. Here, all of the following conditions must be satisfied:\n\n*   $a < b + c$\n*   $b < c + a$\n*   $c < a + b$\n\nHow many different triangles can be formed? Two triangles are considered different when there is a stick used in only one of them.\n\n## Constraints\n\n*   All values in input are integers.\n*   $3 \\leq N \\leq 2 \\times 10^3$\n*   $1 \\leq L_i \\leq 10^3$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$L_1$ $L_2$ $...$ $L_N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc143_d","tags":[],"sample_group":[["4\n3 4 2 1","1\n\nOnly one triangle can be formed: the triangle formed by the first, second, and third sticks."],["3\n1 1000 1","0\n\nNo triangles can be formed."],["7\n218 786 704 233 645 728 389","23"]],"created_at":"2026-03-03 11:01:14"}}