You are playing a game called Guru Guru Gururin. In this game, you can move with the vehicle called Gururin. There are two commands you can give to Gururin: 'R' and 'L'. When 'R' is sent, Gururin rotates clockwise by 90 degrees. Otherwise, when 'L' is sent, Gururin rotates counterclockwise by 90 degrees.

During the game, you noticed that Gururin obtains magical power by performing special commands. In short, Gururin obtains magical power every time when it performs one round in the clockwise direction from north to north. In more detail, the conditions under which magical power can be obtained is as follows.

* At the beginning of the special commands, Gururin faces north.
* At the end of special commands, Gururin faces north.
* Except for the beginning and the end of special commands, Gururin does not face north.
* During the special commands, Gururin faces north, east, south, and west one or more times, respectively, after the command of 'R'.



At the beginning of the game, Gururin faces north. For example, if the sequence of commands Gururin received in order is 'RRRR' or 'RRLRRLRR', Gururin can obtain magical power. Otherwise, if the sequence of commands is 'LLLL' or 'RLLR', Gururin cannot obtain magical power.

Your task is to calculate how many times Gururin obtained magical power throughout the game. In other words, given the sequence of the commands Gururin received, calculate how many special commands exists in it.



Input

The input consists of a single test case in the format below.


$S$


The first line consists of a string $S$, which represents the sequence of commands Gururin received. $S$ consists of 'L' and 'R'. The length of $S$ is between $1$ and $10^3$ inclusive.

Output

Print the number of times Gururin obtained magical power throughout the game in one line.

Examples

Input

RRRRLLLLRRRR


Output

2


Input

RLLRLLLLRRRLLLRRR


Output

0


Input

LR


Output

0


Input

RRLRRLRRRRLRRLRRRRLRRLRRRRLRRLRR


Output

4
    #include <bits/stdc++.h>

                                            //    #include <boost/multiprecision/cpp_int.hpp>
 
                               	       #define int long long
                                                #define inf  1000000007
                                              #define pa pair<int,int>
                                               #define pad pair<double,double>
                                                #define ll long long
                                                #define pal pair<double,double>
                                                #define ppap pair<pa,int>
                                          #define PI 3.14159265358979323846
                                                #define paa pair<pa,pa>
                                                #define  mp make_pair
                                                #define  pb push_back
                                                #define EPS (1e-10)
                                                #define equals(a,b) (fabs((a)-(b))<EPS)
                                            //    #define double long double
        int dx[4]={0,-1,0,1};
        int dy[4]={1,0,-1,0};
                                                using namespace std;
                                       			class pa3{
                                                	public:
                                                	int x,y,z;
                                                	pa3(int x=0,int y=0,int z=0):x(x),y(y),z(z) {}
                                                	bool operator < (const pa3 &p) const{
                                                		if(x!=p.x) return x<p.x;
                                                		if(y!=p.y) return y<p.y;
                                                		 return z<p.z;
                                                		//return x != p.x ? x<p.x: y<p.y;
                                                	}
                                       				bool operator > (const pa3 &p) const{
                                                		if(x!=p.x) return x>p.x;
                                                		if(y!=p.y) return y>p.y;
                                                		 return z>p.z;
                                                		//return x != p.x ? x<p.x: y<p.y;
                                                	}
                                                	bool operator == (const pa3 &p) const{
                                                		return x==p.x && y==p.y && z==p.z;
                                                	}
                                                		bool operator != (const pa3 &p) const{
                                                			return !( x==p.x && y==p.y && z==p.z);
                                                	}
                                                
                                                };
                                                
                                                class pa4{
                                                	public:
                                                	int x;
                                                	int y,z,w;
                                                	pa4(int x=0,int y=0,int z=0,int w=0):x(x),y(y),z(z),w(w) {}
                                                	bool operator < (const pa4 &p) const{
                                                		if(x!=p.x) return x<p.x;
                                                		if(y!=p.y) return y<p.y;
                                                		if(z!=p.z)return z<p.z;
                                                		return w<p.w;
                                                		//return x != p.x ? x<p.x: y<p.y;
                                                	}
                                                	bool operator > (const pa4 &p) const{
                                                		if(x!=p.x) return x>p.x;
                                                		if(y!=p.y) return y>p.y;
                                                		if(z!=p.z)return z>p.z;
                                                		return w>p.w;
                                                		//return x != p.x ? x<p.x: y<p.y;
                                                	}
                                                	bool operator == (const pa4 &p) const{
                                                		return x==p.x && y==p.y && z==p.z &&w==p.w;
                                                	}
                                                	
                                                	bool operator != (const pa4 &p) const{
                                                		return !(x==p.x && y==p.y && z==p.z &&w==p.w);
                                                	}
                                                		
                                                
                                                };
                                                class pa2{
                                                	public:
                                                	int x,y;
                                                	pa2(int x=0,int y=0):x(x),y(y) {}
                                                	pa2 operator + (pa2 p) {return pa2(x+p.x,y+p.y);}
                                                	pa2 operator - (pa2 p) {return pa2(x-p.x,y-p.y);}
                                                	bool operator < (const pa2 &p) const{
                                                		return x!= p.x ? x<p.x: y<p.y;
                                                	}
                                                	bool operator > (const pa2 &p) const{
                                                		return x != p.x ? x>p.x: y>p.y;
                                                	}
                                                	bool operator == (const pa2 &p) const{
                                                		return abs(x-p.x)==0 && abs(y-p.y)==0;
                                                	}
                                                	bool operator != (const pa2 &p) const{
                                                		return !(abs(x-p.x)==0 && abs(y-p.y)==0);
                                                	}
                                                		
                                                
                                                };
                                                
                                              
                                                
                                                       #define ppa pair<int,pas>
                                                class Point{
                                                	public:
                                                	double x,y;
                                                	Point(double x=0,double y=0):x(x),y(y) {}
                                                	Point operator + (Point p) {return Point(x+p.x,y+p.y);}
                                                	Point operator - (Point p) {return Point(x-p.x,y-p.y);}
                                                	Point operator * (double a) {return Point(x*a,y*a);}
                                                	Point operator / (double a) {return Point(x/a,y/a);}
                                                	double absv() {return sqrt(norm());}
                                                	double norm() {return x*x+y*y;}
                                                	bool operator < (const Point &p) const{
                                                		return x != p.x ? x<p.x: y<p.y;
                                                	}
                                                	bool operator == (const Point &p) const{
                                                		return fabs(x-p.x)<EPS && fabs(y-p.y)<EPS;
                                                	}
                                                };
                                                typedef Point Vector;
                                         #define pl pair<int,pas>
                                                struct Segment{
                                                Point p1,p2;
                                                };
                                                 double dot(Vector a,Vector b){
                                                	return a.x*b.x+a.y*b.y;
                                                }
                                                double cross(Vector a,Vector b){
                                                	return a.x*b.y-a.y*b.x;
                                                }
                                            
                    bool parareru(Point a,Point b,Point c,Point d){
                    //	if(abs(cross(a-b,d-c))<EPS)cout<<"dd "<<cross(a-b,d-c)<<endl;
                    	return abs(cross(a-b,d-c))<EPS;
                    }
                    double distance_ls_p(Point a, Point b, Point c) {
                      if ( dot(b-a, c-a) < EPS ) return (c-a).absv();
                      if ( dot(a-b, c-b) < EPS ) return (c-b).absv();
                      return abs(cross(b-a, c-a)) / (b-a).absv();
                    }
                    bool is_intersected_ls(Segment a,Segment b) {
                    	if(a.p1==b.p1||a.p2==b.p1||a.p1==b.p2||a.p2==b.p2) return 1;
                    	if(parareru((a.p2),(a.p1),(a.p1),(b.p2))&&parareru((a.p2),(a.p1),(a.p1),(b.p1))){
                    //		cout<<"sss"<<endl;
                    		if(dot(a.p1-b.p1,a.p1-b.p2)<EPS) return true;
                    		if(dot(a.p2-b.p1,a.p2-b.p2)<EPS) return true;
                    		if(dot(a.p1-b.p1,a.p2-b.p1)<EPS) return true;
                    		if(dot(a.p1-b.p2,a.p2-b.p2)<EPS) return true;
                    		return false;
                    	}
                      else return ( cross(a.p2-a.p1, b.p1-a.p1) * cross(a.p2-a.p1, b.p2-a.p1) < EPS ) && ( cross(b.p2-b.p1, a.p1-b.p1) * cross(b.p2-b.p1, a.p2-b.p1) < EPS );
                    }
                     
                    double segment_dis(Segment a,Segment b){
                    	if(is_intersected_ls(a,b))return 0;
                    	double r=distance_ls_p(a.p1, a.p2, b.p1);
                    	r=min(r,distance_ls_p(a.p1, a.p2, b.p2));
                    	r=min(r,distance_ls_p(b.p1, b.p2, a.p2));
                    	r=min(r,distance_ls_p(b.p1, b.p2, a.p1));
                    	return r;
                    }
                    Point intersection_ls(Segment a, Segment b) {
                      Point ba = b.p2-b.p1;
                      double d1 = abs(cross(ba, a.p1-b.p1));
                      double d2 = abs(cross(ba, a.p2-b.p1));
                      double t = d1 / (d1 + d2);
                     
                      return a.p1 + (a.p2-a.p1) * t;
                    }
                     
                                    string itos( int i ) {
                                    ostringstream s ;
                                    s << i ;
                                    return s.str() ;
                                    }
                                     
                                    int gcd(int v,int b){
                                    	if(v==0) return b;
                                    	if(v>b) return gcd(b,v);
                                    	if(v==b) return b;
                                    	if(b%v==0) return v;
                                    	return gcd(v,b%v);
                                    }
                     
                                    double distans(double x1,double y1,double x2,double y2){
                                    	double rr=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
                                    	return sqrt(rr);
                                    	
                                    }
                                                        /*
        double bekid(double w,int r){
        	if(r==0) return 1.0;
        	if(r==1) return w;
        	if(r%2) return bekid(w,r-1)*w;
        	double f=bekid(w,r/2);
        	return f*f;
        }*/
                                    int mod;
                    int beki(int wa,int rr,int warukazu){
                    	if(rr==0) return 1%warukazu;
                    	if(rr==1) return wa%warukazu;
                    	if(rr%2==1) return (beki(wa,rr-1,warukazu)*wa)%warukazu;
                    	int zx=beki(wa,rr/2,warukazu);
                    	return (zx*zx)%warukazu;
                    }
                          /*          
                    int pr[401000];
                    int inv[401000];
                   
                   

                  
        			int comb(int nn,int rr){
        				int r=pr[nn]*inv[rr];
        				r%=mod;
        				r*=inv[nn-rr];
        				r%=mod;
        				
        				return r;
        			}
                  
                    void gya(int ert){
                    	pr[0]=1;
                    	for(int i=1;i<ert;i++){
                    		pr[i]=(pr[i-1]*i)%mod;
                    	}
                    	for(int i=0;i<ert;i++) inv[i]=beki(pr[i],mod-2,mod);
                    	
                    }
                    */
                    
                  //   cin.tie(0);
        		//	ios::sync_with_stdio(false);
        			//priority_queue<pa3,vector<pa3>,greater<pa3>> pq;            
                     //sort(ve.begin(),ve.end(),greater<int>());

vector<int> ve;


  signed main(){
 	              cin.tie(0);
   		ios::sync_with_stdio(false);
int ima=0;
  	ve.pb(0);
  	string s;
  	cin>>s;
  	for(auto c:s){
  		if(c=='R')ima++;
  		else ima--;
  		if(ima%4==0)ve.pb(ima);
  	}
  	int l=ve.size();
  	int ans=0;
  	for(int i=0;i<l-1;i++)if(ve[i]<ve[i+1])ans++;
  	cout<<ans<<endl;
  	return 0;
  	
               }
                
                
                



