Compression

AtCoder
IDasaporo_b
Time2000ms
Memory256MB
Difficulty
Takahashi found an integer sequence $(A_1,A_2,...,A_N)$ with $N$ terms. Since it was too heavy to carry, he decided to compress it into a single integer. The compression takes place in $N-1$ steps, each of which shorten the length of the sequence by $1$. Let $S$ be a string describing the steps, and the sequence on which the $i$\-th step is performed be $(a_1,a_2,...,a_K)$, then the $i$\-th step will be as follows: * When the $i$\-th character in $S$ is `M`, let $b_i = max(a_i,a_{i+1})$ $(1 ≦ i ≦ K-1)$, and replace the current sequence by $(b_1,b_2,...,b_{K-1})$. * When the $i$\-th character in $S$ is `m`, let $b_i = min(a_i,a_{i+1})$ $(1 ≦ i ≦ K-1)$, and replace the current sequence by $(b_1,b_2,...,b_{K-1})$. Takahashi decided the steps $S$, but he is too tired to carry out the compression. On behalf of him, find the single integer obtained from the compression. ## Constraints * $2 ≦ N ≦ 10^5$ * $1 ≦ A_i ≦ N$ * $S$ consists of $N-1$ characters. * Each character in $S$ is either `M` or `m`. ## Input The input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ … $A_N$ $S$ ## Partial Scores * In the test set worth $400$ points, there exists $i (1 ≦ i < N-1)$ such that the first $i$ characters in $S$ are `M`, and the remaining characters are `m`, that is, $S$ is in the form `M...Mm...m`. * In the test set worth $800$ points, the odd-number-th characters in $S$ are `M`, and the even-number-th characters are `m`, that is, $S$ is in the form `MmMmMm...`. [samples]
Samples
Input #1
4
1 2 3 4
MmM
Output #1
3

The initial sequence $( 1 , 2 , 3 , 4 )$ is compressed as follows:

*   After the first step, the sequence is $( 2 , 3 , 4 )$.
*   After the second step, the sequence is $( 2 , 3 )$.
*   After the third step, the sequence is $( 3 )$.

Thus, the single integer obtained from the compression is $3$.
Input #2
5
3 4 2 2 1
MMmm
Output #2
2
Input #3
10
1 8 7 6 8 5 2 2 6 1
MmmmmMMMm
Output #3
5
Input #4
20
12 7 16 8 7 19 8 19 20 11 7 13 20 3 4 11 19 11 15 5
mMMmmmMMMMMMmMmmmMM
Output #4
11
API Response (JSON)
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    "name": "Compression",
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      "content": "Takahashi found an integer sequence $(A_1,A_2,...,A_N)$ with $N$ terms. Since it was too heavy to carry, he decided to compress it into a single integer. The compression takes place in $N-1$ steps, ea",
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    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
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    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "asaporo_b"
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      "statement_type": "Markdown",
      "content": "Takahashi found an integer sequence $(A_1,A_2,...,A_N)$ with $N$ terms. Since it was too heavy to carry, he decided to compress it into a single integer.\nThe compression takes place in $N-1$ steps, ea...",
      "is_translate": false,
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    }
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}
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