var('x,y,z,w')
h(x,y,z,w)=x^20+y^20+z^20+w^20
r(a,b,c,d)=0
for i in range(7):
    g(x,y,z)=h(x,y,z,0)
    q(a,b,c)=0
    for n in range(8):
        f(x,y)=g(x,y,0)
        p(a,b)=0 
        for m in range(11):
            p(a,b)=p(a,b)+f(a,0)*b^m
            f(x,y)=expand((f(x,y)-f(x+y,0))/x/y)
        q(a,b,c)=q(a,b,c)+p(a,b)*c^n
        g(x,y,z)=expand((g(x,y,z)-p(x+y+z,x*y+x*z+y*z))/x/y/z) 
    r(a,b,c,d)=r(a,b,c,d)+q(a,b,c)*d^i 
    h(x,y,z,w)=expand((h(x,y,z,w)-q(x+y+z+w,x*y+x*z+x*w+y*z+y*w+z*w,x*y*z+x*y*w+x*z*w+y*z*w))/x/y/z/w)
print (expand(r(x+y+z+w,x*y+x*z+x*w+y*z+y*w+z*w,x*y*z+x*y*w+x*z*w+y*z*w,x*y*z*w)))