I want to use van kampen theorem to show that the fundamental group of wedge union of two spheres is zero,I know that I must choose $U$ and $V$ which they are open and its union is the whole space.I know that I can't take $U$ and $V$ as two spheres but I can take open set containing one whole sphere,in that case they are open,the intersection is one point,and the union is whole space and every thing will be done,but I don't know what is that open subset which contains one whole sphere.
this problem is almost done,please help me to make it complete.thank you very much.