const Main = (input) =>{
	var xs = input.trim().split(' ').map(v=>parseInt(v,10));
	var ans = xs[0] - xs[1];
    if(ans >= 0){
    console.log(ans+0);
    }else if(ans < 0){
    console.log(0+0);
    }
}

Main(require("fs").readFileSync("/dev/stdin","utf8"));