#ASK USER TO INPUT MORE THAN ONE DIGIT
#CALCULATE ITS SUM
# num=input("enter your number : ")
# total=0
# i=0
# while i < int(len(num)):
#     total+=int(num[i])
#     i+=1
# print(total)

number=input("enter your number : ")
space=0
j=0
while j<int(len(number)):
    space+=int(number[j])
    j+=1
print(space)
