function Main(input) {
    input = input.split("\n");
    const s = input[0];
    let n = s.match(/\d/g);
    let res = 0;
    if (n) {
        n = n.map(a=>parseInt(a));
        res = n.reduce((x,y)=>x+y);
    }
    console.log(res);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));