num=input()

if len(num)<4:
    print(num)
    exit()
    
n=len(num)%3    
if n!=0:
    print(num[0:n]+",",end="")

for i in range(n,len(num),3):
    if i==len(num)-3:
        print(num[i:i+3])
    else:
        print(num[i:i+3]+",",end="")