What is the output for the following code?

#include stdio.h
void solve() {
    int a[] = {1, 2, 3, 4, 5};
    int sum = 0;
    for(int i = 0; i  5; i++) {
        if(i % 2 == 0) {
            sum += *(a + i);
        }
        else {
            sum -= *(a + i);
        }
    }
    printf("%d", sum);
}
int main() {
 solve();
 return 0;
}