import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.container;

void main() {
    readln.chomp.map!"a - '0'".sum.writeln;
}


void readInput(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg ; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront;
    }
    if (!line.empty) {
        throw new Exception("args num < input num");
    }
}