C++ codes for counting saving according to the number of days

Say you need to save RM according to the number of day in a year.

Day 1 in Jan =RM1
Day 2 in Jan =RM2

Day 365 in Dec = RM365


which is quite impossible at the end of the year.. because it's freaking a lot.

Anyway a friend want to count that hence I wrote my simple C++ program;

#include
using namespace std;
int main()
{
int sum;
for (int i=1;i<=365;i++)
{
sum+=i;
}
cout<<"Sum is "<return 0;
}

That's all.