GCC fail

a.c

int k(int a) {
	int b = a;
	switch(a) {
	case 1:
		b+=1;break;
	case 2:
		b+=2;break;
	case 3:
		b+=3;break;
	case 4:
		b+=4;break;
	case 5:
		b+=5;break;
	case 6:
		b+=6;break;
	default:
		b+=7;
	}
	return b;
}