0 and 1 is trivial solution.
Let x solution it must satisfy for follow requirements:
{x=0(mod p);x=1(mod q);} or
{x=0(mod q);x=1(mod p);}
We can find 2 solution for these equation let it be x1,x2;
And all solution will satisyf for follow requirements (x1+lcm(p,q))mod n,(x2+lcm(p,q))mod n;
but lcm(p,q)==n we have only for solutions
0 1 x1 x2;
Sorry for bad English!

very remarkable