"use strict";

const main = arg => {
    arg = arg.trim().split("\n");
    const A = parseInt(arg[0].split(" ")[0]);
    const B = parseInt(arg[0].split(" ")[1]);
    const C = parseInt(arg[0].split(" ")[2]);
    
    // let temp = Math.sqrt(A) + Math.sqrt(B);
    
    console.log(A + B < C ? "Yes" : "No")
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));