def f(x):
    if x==0:
        return 1,0
    if x%2:
        p,q = f(x-1)
        return p*c%MOD, (q+b)*c%MOD
    else:
        p,q = f(x//2)
        return p*p%MOD, (p*q+q)%MOD

b,c,d = map(int,input().split())
MOD = 10**9+7
print(f(d)[1])