#include <bits/stdc++.h>
const int Maxn = 1e6 + 10;
const long long OO = 1e9;
const double PI = 3.142857142857143;
const long long mod = 1e8;
using namespace std;
int dp[110][110][11][11];
int n1, n2, k1, k2;
int solve(int i, int j, int q1, int q2) {
  if (i > n1 || j > n2 || q1 > k1 || q2 > k2) {
    return 0;
  }
  if (i == n1 && j == n2) {
    return 1;
  }
  if (dp[i][j][q1][q2] != -1) {
    return dp[i][j][q1][q2];
  }
  int& r = dp[i][j][q1][q2];
  r = 0;
  if (i < n1) r += (solve(i + 1, j, q1 + 1, 0) % mod);
  if (j < n2) r += (solve(i, j + 1, 0, q2 + 1) % mod);
  r %= mod;
  return r;
}
int main(void) {
  ios::sync_with_stdio(false);
  cin >> n1 >> n2 >> k1 >> k2;
  memset(dp, -1, sizeof dp);
  cout << solve(0, 0, 0, 0);
  return 0;
}
