{"problem":{"name":"Postdocs","description":{"content":"For a string $S$ consisting of the uppercase English letters `P` and `D`, let the _doctoral and postdoctoral quotient_ of $S$ be the total number of occurrences of `D` and `PD` in $S$ as contiguous su","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"nomura2020_b"},"statements":[{"statement_type":"Markdown","content":"For a string $S$ consisting of the uppercase English letters `P` and `D`, let the _doctoral and postdoctoral quotient_ of $S$ be the total number of occurrences of `D` and `PD` in $S$ as contiguous substrings. For example, if $S =$ `PPDDP`, it contains two occurrences of `D` and one occurrence of `PD` as contiguous substrings, so the doctoral and postdoctoral quotient of $S$ is $3$.\nWe have a string $T$ consisting of `P`, `D`, and `?`.\nAmong the strings that can be obtained by replacing each `?` in $T$ with `P` or `D`, find one with the maximum possible doctoral and postdoctoral quotient.\n\n## Constraints\n\n*   $1 \\leq |T| \\leq 2 \\times 10^5$\n*   $T$ consists of `P`, `D`, and `?`.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$T$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"nomura2020_b","tags":[],"sample_group":[["PD?D??P","PDPDPDP\n\nThis string contains three occurrences of `D` and three occurrences of `PD` as contiguous substrings, so its doctoral and postdoctoral quotient is $6$, which is the maximum doctoral and postdoctoral quotient of a string obtained by replacing each `?` in $T$ with `P` or `D`."],["P?P?","PDPD"]],"created_at":"2026-03-03 11:01:14"}}