#include <bits/stdc++.h>
using namespace std;
int l_f, l_h;
long long int dp[101][101][11][11];
int getans(int f, int h, int k1, int k2) {
  int x = 0, y = 0;
  if ((f + h) == 0) return 1;
  if (dp[f][h][k1][k2] != -1) return dp[f][h][k1][k2];
  if (f > 0 && k1 > 0) x = getans(f - 1, h, k1 - 1, l_h);
  if (h > 0 && k2 > 0) y = getans(f, h - 1, l_f, k2 - 1);
  return dp[f][h][k1][k2] = (x + y) % 100000000;
}
int main() {
  int t = 1;
  while (t--) {
    int n1, n2;
    cin >> n1 >> n2 >> l_f >> l_h;
    memset(dp, -1, sizeof(dp));
    int ans = getans(n1, n2, l_f, l_h);
    cout << ans << '\n';
  }
}
