b,c,d=map(int,input().split()) M=10**9+7 l=2 def seki(a,b): c=[[0]*l for i in range(l)] for i in range(l): for j in range(l): for k in range(l): c[i][j]+=a[i][k]*b[k][j] c[i][j]%=M return c A=[[c,b*c],[0,1]] B=[[1,0],[0,1]] for i in range(60): if (d>>i)&1: B=seki(A,B) A=seki(A,A) print(B[0][1])