function Main(input) {
	input = input.trim().split("\n").map(function(x) { return x.split(" ")});
	var N = parseInt(input[0][0], 10);
	var H = parseInt(input[1][0], 10);
	var W = parseInt(input[2][0], 10);
	console.log((N - H + 1) * (N - W + 1));
}

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