#coding utf-8
#https://yukicoder.me/problems/no/656
#No.656 golf
s_scr = 0
scr = str(input())
for i in range(len(scr)):
    if 0 < int(scr[i]) <= 10:
        s_scr = s_scr + int(scr[i])
    elif 0 == int(scr[i]):
        s_scr = s_scr + 10
print(s_scr)