#include <bits/stdc++.h>
using namespace std;
long long n,x,t;
int main()
{
cin>>n;
t=0;
while (n>0)
{
x=n%10;
t=t+x;
n/=10;
}
cout<<t;
return 0;
}
Var t,n:integer;
begin
write('nhap n = ');readln(n);
while n div 10 <> 0 do
begin
t:=t+(n mod 10);
n:=n div 10;
end;
write('Tong cac chu so cua ',n,' la ',t);
readln;
end.