function Main(input) {
	input = input.split(" ");
	var x = input[0];
    
    var num = x.length;
    var count = Math.ceil(num/2);
    
    var ans = [];
    for(var i = 0; i < count; i++){
        var kisu = x[i*2];
        ans.push(kisu);
    }
    
    ans = ans.join("");
    console.log(ans);
    
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
