import java.util.Scanner;
class Main {
static int getNumb() {
Scanner numb = new Scanner(System.in);
return numb.nextInt();
}
public static void main(String [ ] args) {
int sum = 0;
int x;
while(true) {
x = getNumb();
if(x != 0) {
sum += x;
}
else {
break;
}
}
System.out.print(sum);
}
}