Simplifying code

Answer (c):

int sum(int n) {
	int result = 0, counter= 1;
	loop:
	   result = result+counter;
	   counter= counter+1;
	   if (counter<=n) goto loop;
	return result;
}
void main() { printf("%i", sum(100) ); }

Nb. The preceding code presents how to combine variable declarations.

6 - 10