x=input()
r=""
if len(x)%3!=0:
    r=x[:len(x)%3]+","
    x=x[len(x)%3:]

for i in range(int(len(x)/3-1)+1):
    if i ==0:
        r=r+x[3*(i-1)+3:3*i+3]
    else:
        r=r+","+x[3*(i-1)+3:3*i+3]
print(r)