{"problem":{"name":"ι⊥l","description":{"content":"Three poles stand evenly spaced along a line. Their heights are $a$, $b$ and $c$ meters, from left to right. We will call the arrangement of the poles _beautiful_ if the tops of the poles lie on the s","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc058_a"},"statements":[{"statement_type":"Markdown","content":"Three poles stand evenly spaced along a line. Their heights are $a$, $b$ and $c$ meters, from left to right. We will call the arrangement of the poles _beautiful_ if the tops of the poles lie on the same line, that is, $b-a = c-b$.\nDetermine whether the arrangement of the poles is beautiful.\n\n## Constraints\n\n*   $1 \\leq a,b,c \\leq 100$\n*   $a$, $b$ and $c$ are integers.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$a$ $b$ $c$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc058_a","tags":[],"sample_group":[["2 4 6","YES\n\nSince $4-2 = 6-4$, this arrangement of poles is beautiful."],["2 5 6","NO\n\nSince $5-2 \\neq 6-5$, this arrangement of poles is not beautiful."],["3 2 1","YES\n\nSince $1-2 = 2-3$, this arrangement of poles is beautiful."]],"created_at":"2026-03-03 11:01:14"}}