import numpy as np
a,b,n=map(int,input().split())
m=10**9+7
k=n//2
def dot(A,B):
    n=A.shape[0]
    ans=np.zeros(A.shape,dtype=np.int64)
    A=A%m
    B=B%m
    for i in range(n):
        for j in range(n):
            for k in range(n):
                ans[i,j]=ans[i,j]+(A[i,k]*B[k,j])%m
    return ans            
    
def pow(A,k):
    last=np.eye(A.shape[0])
    cur_A=A
    while True:
        if k==0:
            cur_A=np.eye(A.shape[0])
            break
        elif k%2==0:
            cur_A=dot(cur_A,cur_A)
            k=k/2
        else:
            k=k-1
            last=dot(last,cur_A)
    
    return dot(cur_A,last)

l=1-(n-2*k)
A=np.array([[a*a+b,a],[a*b,b]])
B=pow(A,k)
print(int(B[0,l]))