ss = input()

dd = {}

for i in ss:
    if i in dd:
        dd[i] += 1
    else:
        dd[i] = 1


dd = sorted(dd.items(),key = lambda x:x[0])
dd = {i[0]:i[1] for i in dd}
ans = ''

for item in dd.items():
    ans += item[0]
    ans += str(item[1])

print(ans)