HackerRank C++ Input and Output

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
    long double a,b,c,sum=0;

    cin>>a>>b>>c;

    sum=a+b+c;

    cout<<sum;

    return 0;
}