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                    | \_/\_/    |~\|~\|__    \_/| \||\_X\_/|__
                (J U S T   L I K E   E V E R Y O N E   E L S E !)

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*/                              
#include<bits/stdc++.h>
using namespace std;
 
#define fastio ios_base::sync_with_stdio(0); cin.tie(0)
#define LL long long 
#define mod 1000000007 
#define all(v) v.begin(),v.end()
#define pr(v) pair<v,v>
#define pb push_back
#define FOR(i, j, k) for (auto i=j ; i<k ; i++)
#define ROF(i, j, k) for (auto i=j ; i>=k ; i--) 
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false); debug("%s time : %.4fs", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))

const long long INF = 1e18;
const long long MAX = 2e5+10;
int main(){
    fastio;
    int t=1;// cin>>t;
    while(t--){
        string s; cin>>s;
        if(s[0]=='R' && s[1]=='R' && s[2]=='R') cout<<3;
       else  if((s[0]=='R' && s[1]=='R') || (s[1]=='R' && s[2]=='R')) cout<<2;
        else if(s[0]=='R'   || s[1]=='R' || s[2]=='R') cout<<1;
        else cout<<0;
    }
}


Measured memory_bytes: 3608