#include <bits/stdc++.h>   using namespace std;   const int INF = 0x3F3F3F3F;   const int NEGINF = 0xC0C0C0C0;   const double EPS = 1e-8;   int cmp(double x, double y = 0, double tol = EPS) {     return (x <= y + tol) ? (x + tol < y) ? -1 : 0 : 1;   }   string s;   bool test(long long inx) {     int pos = 0;     int m = 0;     int im = 0;     for (auto &x : s) {       if (x ==  R )         pos++;       else         pos--;       if (inx >= 0 && pos == inx) pos--;       if (pos < m) {         m = pos;         im = &x - &(s[0]);       }     }     return im == s.size() - 1;   }   int main() {     cin >> s;     if (s.back() ==  R )       for (auto &x : s) x =  R  +  L  - x;     if (test(-1)) {       cout <<  1 n ;       return 0;     } else if (!test(1)) {       cout <<  0 n ;       return 0;     }     long long m = 1, M = 0x7fffffffffffffffll;     long long ans = 1;     while (M >= m) {       long long med = m + (M - m) / 2;       if (test(med)) {         ans = med;         m = med + 1;       } else         M = med - 1;     }     cout << ans << endl;     return 0;   }   