#include <bits/stdc++.h>
using namespace std;
const int mod = 1e8;
int dp[110][110][12][12];
int fm, hm, kf, kh;
int solve(int n1, int n2, int k1, int k2) {
  if (n1 == 0 && n2 == 0) {
    return 1;
  }
  if (dp[n1][n2][k1][k2] != -1) {
    return dp[n1][n2][k1][k2];
  }
  int cnt = 0, r1 = 0, r2 = 0;
  if (n1 > 0 && k1 > 0) {
    r1 = solve(n1 - 1, n2, k1 - 1, kh);
  }
  if (n2 > 0 && k2 > 0) {
    r2 = solve(n1, n2 - 1, kf, k2 - 1);
  }
  cnt += (r1 % mod + r2 % mod) % mod;
  dp[n1][n2][k1][k2] = cnt;
  return dp[n1][n2][k1][k2];
}
int main() {
  memset(dp, -1, sizeof(dp));
  cin >> fm >> hm >> kf >> kh;
  int ans = solve(fm, hm, kf, kh);
  cout << ans;
}
