import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    auto s = readln.chomp;
    int ans = 0;
    foreach (c; s) {
        if (c == '0') ans += 10;
        else ans += c - '0';
    }
    writeln(ans);
}