import math

def main():
    s = input("Vnesi string: ")
    i = 0
    res = ""
    while i < len(s):
        cnt = 0
        for j in range(i, len(s)):
            if s[i] != s[j]:
                break
            cnt += 1
        res += str(cnt) + s[i]
        i += cnt
    print(res)



if __name__ == "__main__":
    main()