#include <bits/stdc++.h>
using namespace std;
int limit_h, limit_f;
int dp[101][101][11][11];
int mod = 1e8;
int solve(int f, int h, int k1, int k2) {
  if (dp[f][h][k1][k2] != -1) return dp[f][h][k1][k2];
  if ((f + h) == 0) return 1;
  int x = 0;
  if (f > 0 && k1 > 0) x = solve(f - 1, h, k1 - 1, limit_h);
  int y = 0;
  if (h > 0 && k2 > 0) y = solve(f, h - 1, limit_f, k2 - 1);
  return dp[f][h][k1][k2] = (x + y) % mod;
}
int main() {
  int t;
  int n1, n2;
  cin >> n1 >> n2 >> limit_f >> limit_h;
  memset(dp, -1, sizeof(dp));
  cout << solve(n1, n2, limit_f, limit_h);
}
