codeforce - Nearest Interesting Number

#include<bits/stdc++.h>
using namespace std;
#define fast()(ios_base::sync_with_stdio(0),cin.tie(NULL));
typedef long long ll;
int main()
{
    fast();
    int n,sum=0,x;
    cin>>n;
    x=n;
    while(n>0)
    {
        sum+=(n%10);
        n/=10;
    }
    //cout<<sum<<endl;
    if(sum%4==0)
        cout<<x<<endl;
    else
    {
        while(1)
        {
            x+=1;
            n=x;
            sum=0;
            while(n>0)
            {
                sum+=(n%10);
                n/=10;
            }
            //cout<<sum<<endl;
            if(sum%4==0)
            {
                cout<<x<<endl;
                return 0;
            }

        }

    }

    return 0;
}