import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class UniqueChar {
    public static void main(String[] args) {
        String inputString1 = "dfeddsaagrtrf";
       // String inputString1 = "GeeksForGeeks";
        // String inputString1 = "GeeksAForGeeks";

        String sym = searchForSymbol(inputString1);
        System.out.println("returned: " + sym);
    }

    private static String searchForSymbol(String inputString1) {
        List<String> unique = new ArrayList<>();
        String[] chars = inputString1.split("");

        List<String> chrs = Arrays.asList(chars);
        System.out.println("chrs: " + chrs);
        int size = chrs.size()-1;

        for (int i = 0; i <= size; i++) {
            String symbol = chrs.get(i);
            System.out.println("search for symbol: " + symbol);
            boolean isDuplicated = false;

            for (int j = 0; j <= size; j++) {
                if (j!=i) {
                    if (symbol.equals(chrs.get(j))) {
                        System.out.println("paired symbol " + symbol);
                            isDuplicated = true;
                        }
                    }
                }

            if (!isDuplicated) {
                if (!unique.contains(symbol)) {
                    System.out.println("new un-paired symbol " + symbol);
                    unique.add(symbol);
                }
            }
        }
        System.out.println("unique list" + unique);
        return unique.get(0);
    }
}