function main(arg) {
    var tmp = arg.split("\n").map(n=>parseInt(n));
    var N = tmp[0];
    var H = tmp[1];
    var W = tmp[2];
    
    console.log( (1 + (N - W)) * (1 + (N - H)));
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));