function Main(input){
	var xs = input.trim().split(' ').map(v=>parseInt(v,10));
    var sum = 0;
    for(i = 0; i<xs.length; i++){
    sum += xs[i];
    }
    console.log(Math.ceil(sum/xs.length));
}
Main(require('fs').readFileSync("/dev/stdin","utf8"));