import sequtils,algorithm,math,tables
import sets,intsets,queues,heapqueue,bitops,strutils
template times*(n:int,body) = (for _ in 0..<n: body)
template `max=`*(x,y) = x = max(x,y)
template `min=`*(x,y) = x = min(x,y)

proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    let k = getchar_unlocked()
    if k < '0': break
    result = 10 * result + k.ord - '0'.ord

const MOD = 1000000007
proc pow(c,d:int) : int = # c^d
  if d == 0 : return 1
  if d == 1 : return c mod MOD
  let pow2 = pow(c,d div 2) mod MOD
  if d mod 2 == 0 : return (pow2 * pow2) mod MOD
  return (((pow2 * pow2) mod MOD) * (c mod MOD)) mod MOD
proc powSum(c,d:int):int =
  if d == 0: return 1
  if d == 1: return (c + 1) mod MOD
  let powSum2 = powSum(c,(d-1) div 2) mod MOD
  if d mod 2 == 1:
    return (powSum2 * (1 + pow(c,1 + d div 2) mod MOD) mod MOD) mod MOD
  return ((powSum2 * (1 + pow(c, d div 2) mod MOD) mod MOD) mod MOD + pow(c,d)) mod MOD

let b = scan()
let c = scan()
let d = scan()
echo (((b mod MOD * powSum(c,d) mod MOD) mod MOD) + MOD - b mod MOD)mod MOD
# b \Sigma{ c ^i }[i=[0,d]]