#include <bits/stdc++.h>
using namespace std;
const int N = 100 + 5;
const int K = 16 + 5;
const long long M = 1e8;
int a, b, n, m;
long long dp[N][N][K][K];
long long solve(int n, int m, int x, int y) {
  if (x > a || y > b || n < 0 || m < 0) return 0;
  if (n == 0 && m == 0) return 1;
  if (dp[n][m][x][y] != -1) return dp[n][m][x][y];
  return dp[n][m][x][y] =
             (solve(n - 1, m, x + 1, 0) + solve(n, m - 1, 0, y + 1)) % M;
}
int main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> m >> a >> b;
  memset(dp, -1, sizeof(dp));
  cout << solve(n, m, 0, 0);
  return 0;
}
