#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n; int a,b,c; cin >> n; a = n % 10; b = n / 10 % 10; c = n / 100; cout << a + b + c; return 0; }