import time
import sys
f=open('in11_6.txt','r')
e=f.readline()
sh=f.readline()
a=sh.split(",")
f.close()
i=0
c=0
no_swap=0
m=len(a)-1
t1=time.clock()
while(i<=m):
    
    if(a[i]=='B'):
        while(1):
            if(a[m]!='B'):
                break
            if(m==i):
                break
            elif(a[m]=='B'):
                m=m-1
        no_swap=no_swap+1
        a[i]=a[m]
        a[m]='B'
        m=m-1
    if(a[i]=='R'):
        while(1):
            
            if(a[c]=='R'and c<m and c!=i):
                c=c+1
            elif(c==i):
                break
            else:
                break
        no_swap=no_swap+1
        a[i]=a[c]
        a[c]='R'
        c=c+1
        
    
    i=i+1               
t2=time.clock()
t=t2-t1
mem=sys.getsizeof(i)+sys.getsizeof(c)+sys.getsizeof(a)+sys.getsizeof(m)
f1=open('out_16_11_6.txt','w')        
#print a
f1.write(str(a))
f1.write("\nNo. of Swaps=%d\nTime taken=%fseconds\nSpace occupied=%d bytes"%(no_swap,t,mem))
f1.close()