Find the output

Question

#include<iostream.h>
void main()
{ long Number = 7583241;
int First=0, Second=0;
do
{ int R=Number%10;
if (R%2==0)
First+=R;
else
Second+=R;
Number /=10;
} while (Number>O);
cout<<First-Second;
}

Answer 1

-2, but there is errors in the example, like 'include <iostream.h>' and 'while (Number > O)', where O is a letter. (I'm using font with slashed zero number to make difference easier between O and 0, 1, I, l and such.)