{"problem":{"name":"Range Set","description":{"content":"Snuke has a string $x$ of length $N$. Initially, every character in $x$ is `0`. Snuke can do the following two operations any number of times in any order: *   Choose $A$ consecutive characters in $x","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"agc045_c"},"statements":[{"statement_type":"Markdown","content":"Snuke has a string $x$ of length $N$. Initially, every character in $x$ is `0`.\nSnuke can do the following two operations any number of times in any order:\n\n*   Choose $A$ consecutive characters in $x$ and replace each of them with `0`.\n*   Choose $B$ consecutive characters in $x$ and replace each of them with `1`.\n\nFind the number of different strings that $x$ can be after Snuke finishes doing operations. This count can be enormous, so compute it modulo $(10^9+7)$.\n\n## Constraints\n\n*   $1 \\leq N \\leq 5000$\n*   $1 \\leq A,B \\leq N$\n*   All values in input are integers.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$ $A$ $B$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"agc045_c","tags":[],"sample_group":[["4 2 3","11\n\nFor example, $x$ can be `0011` or `1111` in the end, but cannot be `0110`."],["10 7 2","533"],["1000 100 10","828178524"]],"created_at":"2026-03-03 11:01:13"}}