var input: int = [3, 1, 4, 5, 1, 0, 5, 9, 7];
var fuga: int = only(input);

println(fuga);

operation only(input: int){
    var hoge = input.hashCode();
    for(i in input){
        if(sizeof(select j from j in hoge where j == i) > 1){
            delete hoge[. == i];
        }
    }
    return hoge;
}