def trans(num):
num=list(num)
res=''
if len(num)==3:
res=int(num[0])*'B'+int(num[1])*'S'
for i in range(int(num[2])):
res=res+str(i+1)
elif len(num)==2:
res=int(num[0])*'S'
for i in range(int(num[1])):
res=res+str(i+1)
else:
for i in range(int(num[0])):
res=res+str(i+1)
print(res)
if __name__=="__main__":
num=input()
trans(num)