public static void main(String[] args) {
int[] arr1 = { 1, 3, 3, 7 };
int[] arr2 = { 3, 6, 6, 7, 9 };
int[] arr3 = { 1, 3, 8 };
int i;
int j = 0;
int a = 0;
int b = 0;
for (i = 0; i < arr1.length; i++) {
while (j<arr2.length) {
if (arr1[i] == arr2[j]){
b++;
break;
}
j++;
if (j == arr2.length) {
j = 0;
break;
}
}
while (a < arr3.length) {
if (arr1[i] == arr3[a]) {
b++;
break;
}
a++;
if (a == arr3.length) {
a = 0;
break;
}
}
if (b == 2) {
System.out.println(arr1[i]);
break;
}
b = 0;
}
if (b == 0) System.out.println("Число отсутствует");
}