Codeforces Round #388 (Div. 2) 749C Voting 【模拟】

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There are n employees in Alternative Cake Manufacturing (ACM). They are now voting on some very important question and the leading world media are trying to predict the outcome of the vote.

Each of the employees belongs to one of two fractions: depublicans or remocrats, and these two fractions have opposite opinions on what should be the outcome of the vote. The voting procedure is rather complicated:

Each of n employees makes a statement. They make statements one by one starting from employees1 and finishing with employee n. If at the moment when it's time for the i-th employee to make a statement he no longer has the right to vote, he just skips his turn (and no longer takes part in this voting).
When employee makes a statement, he can do nothing or declare that one of the other employees no longer has a right to vote. It's allowed to deny from voting people who already made the statement or people who are only waiting to do so. If someone is denied from voting he no longer participates in the voting till the very end.
When all employees are done with their statements, the procedure repeats: again, each employees starting from1 and finishing with n who are still eligible to vote make their statements.
The process repeats until there is only one employee eligible to vote remaining and he determines the outcome of the whole voting. Of course, he votes for the decision suitable for his fraction.

You know the order employees are going to vote and that they behave optimal (and they also know the order and who belongs to which fraction). Predict the outcome of the vote.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 200 000) — the number of employees.

The next line contains n characters. Thei-th character is 'D' if thei-th employee is from depublicans fraction or 'R' if he is from remocrats.

Output

Print 'D' if the outcome of the vote will be suitable for depublicans and 'R' if remocrats will win.

Examples

Input

5
DDRRR

Output

Input

6
DDRRRR

Output

Note

Consider one of the voting scenarios for the first sample:

Employee 1 denies employee 5 to vote.
Employee 2 denies employee 3 to vote.
Employee 3 has no right to vote and skips his turn (he was denied by employee2).
Employee 4 denies employee 2 to vote.
Employee 5 has no right to vote and skips his turn (he was denied by employee1).
Employee 1 denies employee 4.
Only employee 1 now has the right to vote so the voting ends with the victory of depublicans.

题意：有n个人在一起投票，他们分为D和R两个阵营，并且按照顺序投票。在前面投票的人可以选择让在他之后的某一个投票者出局。出局后无法再参加投票。而这个人（让别人出局的那个人）将会跳过本轮投票，等待下一轮投票。问你最后哪个阵营会胜利？

思路：只要遵循两个条件：编号在前的人可以让编号在后的人出局。

一个阵营没有人在场时。这个阵营就输了。

用两个对列进行模拟即可。两个对列分分别对应两个阵营。当一个阵营为空时。这个阵营就输了。

#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define M(a)  memset(a,0,sizeof(a))
int main()
{
    int n;
    char temp;
    queue<int>d;
    queue<int>r;
    while(~scanf("%d",&n))
    {
        for(int i = 0; i < n; i++)
        {
            cin>>temp;
            if(temp == 'D')
            {
                d.push(i);
            }
            else
                r.push(i);
        }
        while(!d.empty() && !r.empty())
        {
            int froa,frob;
            froa = d.front();
            frob = r.front();
            d.pop();
            r.pop();
            if(froa <frob)
            {
                d.push(froa + n);
            }
            else
                r.push(frob + n);
        }
        if(d.empty())
        {
            cout<<"R"<<endl;
        }
        else
        {
            cout<<"D"<<endl;
        }

        while(!d.empty())
        {
            d.pop();
        }
        while(!r.empty())
        {
            r.pop();
        }
    }
    return 0;
}

Codeforces Round #388 (Div. 2) 749C Voting 【模拟】

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