def fact(n)
    return 1 if n == 0
    (1..n).inject(:*)
end

def comb(n, k)
    fact(n) / fact(k) / fact(n-k)
end

n, m, r = gets.split.map &:to_i

r -= n * m
if r >= 0
    p comb(r + n - 1, r)
else
    p 0
end