import numpy as np
import sys

sys.setrecursionlimit(10 ** 6)
def MI(): return map(int, sys.stdin.readline().split())

def main():
    md = 10 ** 9 + 7
    b,c,d=MI()
    b,c=b%md,c%md
    m=[[c,0],[1,1]]
    m=np.array(m,dtype="i8")
    pm=np.eye(2,dtype="i8")
    while d>0:
        if d&1:
            pm=np.dot(pm,m)
            pm%=md
        d>>=1
        m=np.dot(m,m)
        m%=md
    a0=[0,b*c%md]
    a0=np.array(a0,dtype="i8")
    ans=np.dot(a0,pm)[0]%md
    print(ans)

main()