import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum MO = 10L^^9 + 7;
enum LIM = 3 * 10^^6;

long[] inv, fac, invFac;
void prepare() {
  inv = new long[LIM];
  fac = new long[LIM];
  invFac = new long[LIM];
  inv[1] = 1;
  foreach (i; 2 .. LIM) {
    inv[i] = MO - ((MO / i) * inv[cast(size_t)(MO % i)]) % MO;
  }
  fac[0] = invFac[0] = 1;
  foreach (i; 1 .. LIM) {
    fac[i] = (fac[i - 1] * i) % MO;
    invFac[i] = (invFac[i - 1] * inv[i]) % MO;
  }
}
long binom(long n, long k) {
  if (0 <= k && k <= n) {
    assert(n < LIM);
    return fac[cast(size_t)(n)] * invFac[cast(size_t)(k)] % MO * invFac[cast(size_t)(n - k)] % MO;
  } else {
    return 0;
  }
}

int N, K, D;

void main() {
  /*
  debug {
    foreach (n; 2 .. 12) foreach (k; 2 .. n + 1) {
      int prod = 1;
      for (int m = n; m >= k; m -= (k - 1)) {
        prod *= (m - k + 1);
      }
      int[][] as;
      foreach (p; 0 .. prod) {
        int pp = p;
        auto a = new int[n];
        for (int m = n; m >= k; m -= (k - 1)) {
          const i = p % (m - k + 1);
          p /= (m - k + 1);
          a = a[0 .. i] ~ (a[i .. i + k].sum + 1) ~ a[i + k .. $];
        }
        as ~= a;
      }
      as = as.sort.uniq.array;
      writeln("n = ", n, ", k = ", k);
      foreach (a; as) {
        writeln(a);
      }
    }
  }
  */
  
  prepare();
  
  try {
    for (; ; ) {
      N = readInt();
      K = readInt();
      D = readInt();
      
      int L, M;
      for (M = N; M >= K; M -= (K - 1)) {
        ++L;
      }
      debug {
        writeln("L = ", L, ", M = ", M);
      }
      
      long ans;
      if (D == 1) {
        ans = M;
      } else {
        long dl = 1;
        foreach (l; 0 .. L + 1) {
          // H(M - 1, L - l)
          long tmp = (L - l == 0) ? 1 : binom((M - 1) + (L - l) - 1, L - l);
          ans += tmp * dl;
          ans %= MO;
          dl *= D;
          dl %= MO;
        }
        ans *= M;
        ans %= MO;
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}