public class Solution {

```
public int singleNumber(final List<Integer> A)
{
int checkBit=1;
int result=0;
int totalCheck=32;
//Check each bit for each integer in the array
while (totalCheck>0)
{
int count=0;
for (int j:A)
{
//count number integers with '1' at the check bit
if ((j&checkBit)!=0) count++;
}
//if it is not a multiple of 3,
//then it means the single number does contribute to the count of 1s
//which means at the check bit, the single number is 1, so we make it 1 using OR
if (count%3!=0) result|=checkBit;
totalCheck--;
checkBit<<=1;
}
return result;
}
```

}