### PROBLEM LINK:

**Author**: Shubham Jain

**Tester**: Shubham Jain

**Editorialist**: Shubham Jain

### DIFFICULTY:

Easy

### PREREQUISITES:

Basic Programming, Maths

### PROBLEM:

You’re organizing fresher’s party today. You’re expecting ‘n’ freshers and you’ve already arranged ‘m’ beer cans. You want to distribute all the beers among your juniors in such a way that each fresher receives the same number of beer cans. Note you cannot divide a beer can into halves. Find the minimum number of additional beer cans you must buy so that each fresher receives same number of beer cans.

### EXPLANATION:

There are **n** freshers and **m** beer cans. Then each fresher will get **m/n** number of beer cans.

Now this fraction needs to be a whole number so we calculate the ceiling of **m/n** i.e. **ceil(m/n)**.

Total number of beer cans expected for **n** freshers will be **ceil(m/n) x n**.

Subtracting the **m** beer cans which is already given, we get **(ceil(m/n) x n) – m**.

### AUTHOR’s SOLUTION:

```
#include "iostream"
#include "cmath"
using namespace std;
int main(void){
int t;
cin >> t;
while(t--){
double n, m;
cin >> n >> m;
cout << (int)(ceil(m/n)*n - m) << endl;
}
return 0;
}
```