MOD = 10 ** 9 + 7
INF = 10 ** 11
import sys
sys.setrecursionlimit(100000000)

def main():
    N = input()
    i = len(N) - 3
    while i > 0:
        N = N[:i] + ',' + N[i:]
        i -= 3
    print(N)
if __name__ == '__main__':
    main()