def mod_pow(x,t,mod) :
    if t == 1 :
    	return x
    elif t%2 == 1 :
        y = (mod_pow(x,t//2,mod))
        return (y*y*mod_pow(x,1,mod))%mod
    else :
        y = (mod_pow(x,t//2,mod))
        return (y*y)%mod
	

a,b,t = input().strip().split()

a,b,t = int(a),int(b),int(t)

expected_value = mod_pow(int(0.5*(a+b)),t,10**9+7)

print(int(expected_value))