import sys

if __name__=='__main__':     string=sys.stdin.readline().strip('')     result=''     count=0     for i in range(1,len(string)):         value=string[i-1]         if string[i]==string[i-1]:             count+=1         else:             if count!=0:                 result+=str(count)+value             else:                 result+=value             count=0     print(result)