#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#ifdef DEBUG
#include "../cout11.h"

template <typename T1, typename T2, typename T3> ostream& operator<<(ostream& s, tuple<T1, T2, T3> p) { return s << "(" << get<0>(p) << "," << get<1>(p) << "," << get<2>(p) << ")"; }
template <typename T1, typename T2, typename T3, typename T4> ostream& operator<<(ostream& s, tuple<T1, T2, T3, T4> p) { return s << "(" << get<0>(p) << "," << get<1>(p) << "," << get<2>(p) << "," << get<3>(p) << ")"; }
template <typename T1, typename T2, typename T3, typename T4, typename T5> ostream& operator<<(ostream& s, tuple<T1, T2, T3, T4, T5> p) { return s << "(" << get<0>(p) << "," << get<1>(p) << "," << get<2>(p) << "," << get<3>(p) << "," << get<4>(p) << ")"; }
#undef NDEBUG
#endif
#include <cassert>

#ifdef DEBUG
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define derr(x) cerr << "LINE " << __LINE__ << " : " << #x << " = " << (x) << endl
#else
#define debug(...) true
#define derr(x) true
#endif

typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<llll> vllll;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define eb  emplace_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define repC3(vari,varj,vark,n)  for(int vari=0;vari<(n)-2;++vari)for(int varj=vari+1;varj<(n)-1;++varj)for(int vark=varj+1;vark<(n);++vark)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define whole(f, x, ...)                                     \
    ([&](decltype((x)) whole) {                              \
        return (f)(begin(whole), end(whole), ##__VA_ARGS__); \
    })(x)
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))

#define cons make_pair
#define car first
#define cdr second
#define caar first.first
#define cdar first.second
#define cadr second.first
#define cddr second.second
#define tpl make_tuple

#define clamp(v,lo,hi) min(max(v,lo),hi)
#define ABS(x) max((x),-(x))
#define PQ(T) priority_queue<T,vector<T>,greater<T>>
#define V(x) vector<x>
#define VV(x) vector<vector<x>>
#define VVV(x) vector<vector<vector<x>>>
template <class T> void SORT(T& a) { sort(a.begin(), a.end()); }
template <class T> void REV(T& a) { reverse(a.begin(), a.end()); }
template <class T> int LBIX(const vector<T>& ar, T x) { return lower_bound(ar.begin(), ar.end(), x) - ar.begin(); }
template <class T> int UBIX(const vector<T>& ar, T x) { return upper_bound(ar.begin(), ar.end(), x) - ar.begin(); }

template<typename T1, typename T2> inline void amin(T1 & a, T2 const & b) { if (a>b) a=b; }
template<typename T1, typename T2> inline void amax(T1 & a, T2 const & b) { if (a<b) a=b; }
template<typename T1, typename T2> inline bool chmin(T1 & a, T2 const & b) { if (a>b) {a=b;return true;} else return false;}
template<typename T1, typename T2> inline bool chmax(T1 & a, T2 const & b) { if (a<b) {a=b;return true;} else return false;}
template<typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); }
template<typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); }

// vector<T> dp = make_vector(100, INT_MAX); // dp[100] with initial_value=INT_MAX
template <typename T> vector<T> make_vector(size_t a, T b){ return vector<T>(a, b);}
// auto dp = make_vector(100, 100, 100, INT_MAX); // dp[100][100][100] with initial_value=INT_MAX
template <typename... Ts> auto make_vector(size_t a, Ts... ts) { return vector<decltype(make_vector(ts...))>(a, make_vector(ts...));}

// assign_vector(dp, 100, INT_MAX); // reset dp[100] with value INT_MAX. like fill(v, b)
template <typename T> void assign_vector(vector<T>& v, size_t a, T b){ v.assign(a,b); }
// assign_vector(dp, 100, 100,100, INT_MAX); // reset dp[100][100][100] with value INT_MAX.
// This is much slower than memset().
template <typename V, typename... Ts> void assign_vector(vector<V>& v, size_t a, Ts... ts){ v.assign(a, make_vector(ts...)); }

inline ll square(ll x) { return x * x; }
inline ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }
inline ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }
template <typename T>
inline T mod(T a, T b) { return ((a % b) + b) % b; }

const long double pi = 3.141592653589793238462643383279502884197;

template <typename T>
int find_left(vector<T>& v, T elem) {
    // elemそのものがあればそのindexを、なければ１つ下（左）のindexを返す
    return (int)(upper_bound(v.begin(), v.end(), elem) - v.begin()) - 1;
}
template <typename T>
int find_right(vector<T>& v, T elem) {
    // elemそのものがあればそのindexを、なければ１つ上（右）のindexを返す
    return (int)(lower_bound(v.begin(), v.end(), elem) - v.begin());
}

const ll MOD=1000000007LL;

inline ll ADD(ll x, ll y) { return (x+y) % MOD; }
inline ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
inline ll MUL(ll x, ll y) { return x*y % MOD; }
inline ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
inline ll INV(ll y) { /*assert(y%MOD!=0);*/ return POW(y, MOD-2); }
inline ll DIV(ll x, ll y) { return MUL(x, INV(y)); }
// ll comb(ll n, ll k) { ll v=1; for(ll i=1; i<=k; i++) v = DIV(MUL(v, n-i+1),i); return v; }

#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}

int loadvec(vector<int>& v, int N=-1) {
    if (N == 0) {
        v.clear();
        return 0;
    }
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    // assert(i <= N);
    return i;
}
void read_cr() {
    fgets(_buf, 256, stdin);
}

void horizontal(vector<int>& v) {
    int L = v.size();
    for (int i=0; i<L; ++i) {
        printf("%d%c", v[i], (i==L-1)?'\n':' ');
    }
}
void horizontall(vector<long long>& v) {
    int L = v.size();
    for (int i=0; i<L; ++i) {
        printf("%lld%c", v[i], (i==L-1)?'\n':' ');
    }
}

// ll solve(int N, int M, vi& a, vi& b) {
// ll solve(int N, vi& a, vi& b) {
int solve(string& s){
  if (s=="RRR") return 3;
  if (s=="SSS") return 0;
  if (s=="RRS" || s=="SRR") return 2;
  return 1;
}

int main() {
  string s; cin >> s; cout << solve(s) << endl;
}


Measured memory_bytes: 3592