ifly

// Iflytek_Exam_1.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include<iostream>
#include<vector>
#include<string>

using namespace std;

vector<int> kick(vector<int> queue) {
    vector<int>::iterator it1;
    vector<int>::iterator it2;
    if (queue.size() == 1) return queue;
    for (it1 = queue.begin(), it2 = it1 + 1; it2 != queue.end(); it1++, it2++) {
        if (*it1 == 'R' && *it2 == 'L') {
            if (it1 != queue.begin()) { 
                vector<int>::iterator it3 = it1 - 1; 
                if (*it3 == 'R') {
                    queue.erase(it1);
                    break;
                }
            }
            if (it2 != queue.end() - 1) {
                vector<int>::iterator it4 = it2 + 1;
                if (*it4 == 'L') {
                    queue.erase(it2);
                    break;
                }
            }
            queue.erase(it2);
            break;
        }
    }
    return queue;
}
int check(vector<int> queue) {
    int len = queue.size();
    while (1) {
        queue = kick(queue);
        int currlen = queue.size();
        if (currlen == len) break;
        else len = currlen;
    }
    return queue.size();
}

int main()
{
    char q[1024] = { '' };
    cin >> q;
    //char q[1024] = { "LRRLRL" };
    vector<int> queue;
    for (unsigned int i = 0; i < strlen(q); i++) {
        queue.push_back(q[i]);
    }
    cout<<check(queue);
    getchar();
    return 0;
}