def x(s):
    n = list(map(int, s.split(',')))
    n.sort()
    a = []
    b = n[0]
    k = n[0]
    for i in range(1, len(n)):
        if n[i] == n[i - 1]:
            continue
        if n[i] == n[i - 1] + 1:
            k = n[i]
        else:
            if b == k:
                a.append(str(b))
            else:
                a.append(f"{b}-{k}")
            b = k = n[i]
    if b == k:
        a.append(str(b))
    else:
        a.append(f"{b}-{k}")
    kq = ",".join(a)
    return kq
s = input()
print(x(s))