#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,a, sum = 0; cin >> n; while(n != 0) { a = n % 10; sum += a; n /= 10; } cout<< sum <<endl; return 0; }