import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from math import factorial 
def main():
    n, m, k = map(int, readline().split())
    P = int(1e9)+7

    def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

    c = C(n*m-2, k-2, P)
    s_x = 0
    for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
    s_y = 0
    for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

    ans = (s_x+s_y)*c%P
    print(ans)
if __name__ == '__main__':
    main() import sys sys read = sys.stdin.buffer.read read sys.stdin.buffer.read sys.stdin.buffer sys.stdin sys stdin buffer read readline = sys.stdin.buffer.readline readline sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline readlines = sys.stdin.buffer.readlines readlines sys.stdin.buffer.readlines sys.stdin.buffer sys.stdin sys stdin buffer readlines from math import factorial def main():
    n, m, k = map(int, readline().split())
    P = int(1e9)+7

    def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

    c = C(n*m-2, k-2, P)
    s_x = 0
    for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
    s_y = 0
    for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

    ans = (s_x+s_y)*c%P
    print(ans) main n, m, k = map(int, readline().split()) n map(int, readline().split()) map int readline().split() ().split () readline split m k P = int(1e9)+7 P int(1e9)+7 int(1e9) int 1e9 7 def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

     C a = 1 a 1 for i in range(m):
            a *= (n-i)
            a %= p
         i range(m) range m a *= (n-i) a n-i n i a %= p a p b = factorial(m)%p b factorial(m)%p factorial(m) factorial m p b = pow(b, p-2, p) b pow(b, p-2, p) pow b p-2 p 2 p return a*b%p a*b%p a*b a b p n n m m p p c = C(n*m-2, k-2, P) c C(n*m-2, k-2, P) C n*m-2 n*m n m 2 k-2 k 2 P s_x = 0 s_x 0 for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
     d range(1, m) range 1 m s_x += d*(m-d)*n*n s_x d*(m-d)*n*n d*(m-d)*n d*(m-d) d m-d m d n n s_x %= P s_x P s_y = 0 s_y 0 for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

     d range(1, n) range 1 n s_y += d*(n-d)*m*m s_y d*(n-d)*m*m d*(n-d)*m d*(n-d) d n-d n d m m s_y %= P s_y P ans = (s_x+s_y)*c%P ans (s_x+s_y)*c%P (s_x+s_y)*c s_x+s_y s_x s_y c P print(ans) print ans if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main readline = sys.stdin.buffer.readline sys.stdin.buffer.readline readline readlines = sys.stdin.buffer.readlines sys.stdin.buffer.readlines readlines def main():
    n, m, k = map(int, readline().split())
    P = int(1e9)+7

    def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

    c = C(n*m-2, k-2, P)
    s_x = 0
    for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
    s_y = 0
    for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

    ans = (s_x+s_y)*c%P
    print(ans) def main():
    n, m, k = map(int, readline().split())
    P = int(1e9)+7

    def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

    c = C(n*m-2, k-2, P)
    s_x = 0
    for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
    s_y = 0
    for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

    ans = (s_x+s_y)*c%P
    print(ans) main read = sys.stdin.buffer.read sys.stdin.buffer.read read
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from math import factorial 
def main():
    n, m, k = map(int, readline().split())
    P = int(1e9)+7

    def C(n, m, p):
        a = 1
        for i in range(m):
            a *= (n-i)
            a %= p
        b = factorial(m)%p 
        b = pow(b, p-2, p)
        return a*b%p

    c = C(n*m-2, k-2, P)
    s_x = 0
    for d in range(1, m):
        s_x += d*(m-d)*n*n
        s_x %= P
    s_y = 0
    for d in range(1, n):
        s_y += d*(n-d)*m*m
        s_y %= P

    ans = (s_x+s_y)*c%P
    print(ans)
if __name__ == '__main__':
    main()
