#include <bits/stdc++.h>
using namespace std;
int limit_h, limit_f;
long long int ar[101][101][11][11];
int getAns(int f, int h, int k1, int k2) {
  if ((f + h) == 0) return 1;
  if (ar[f][h][k1][k2] != -1) {
    return ar[f][h][k1][k2];
  }
  int x = 0;
  if (f > 0 && k1 > 0) x = getAns(f - 1, h, k1 - 1, limit_h);
  int y = 0;
  if (h > 0 && k2 > 0) y = getAns(f, h - 1, limit_f, k2 - 1);
  return ar[f][h][k1][k2] = (x + y) % 100000000;
}
int main() {
  int t, a, b;
  t = 1;
  while (t--) {
    cin >> a >> b >> limit_f >> limit_h;
    for (int i = 0; i <= a; i++) {
      for (int j = 0; j <= b; j++) {
        for (int l = 0; l <= limit_f; l++) {
          for (int m = 0; m <= limit_h; m++) {
            ar[i][j][l][m] = -1;
          }
        }
      }
    }
    int x = getAns(a, b, limit_f, limit_h);
    cout << x << endl;
  }
}
