#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 a,ge,shi,bai; cin>>a; ge=a%10; shi=a/10%10; bai=a/100; cout<<ge+shi+bai; return 0;}