def modifiedPower(n,m,mod): #(n**m)%mod
    m=bin(m)[2:]      
    i=len(m)-1
    power=n
    a=1
    while i!=0:
        power = (power * power)%mod
        if m[a]=="1":
            power = (power * n)%mod
        a+=1    
        i-=1
        
    return power

a,b,n=raw_input().split()
a,b,n=[int(a),int(b),int(n)]
print modifiedPower((a+b)/2,n,1000000007)