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

function Main(args){
    const input = args.split("\n");
  	const tmp = input[0];
    var result = '';

    for(var i=0; i<tmp.length; i++){
        result += (i%2 == 0 ? tmp[i] : '');
    }

    console.log(result);
}