# Enter your code here. Read input from STDIN. Print output to STDOUT 

require 'openssl'

def lazy_edv(t, a, b)
  bn = ((a + b) / 2).to_bn
  bn.mod_exp(t, (10**9 + 7)).to_i
end

a, b, t = gets.strip.split(' ').map(&:to_i)

puts lazy_edv(t, a, b)