#include <bits/stdc++.h>
using namespace std;
long long dp[105][105][15][15];
int n, m, a, b;
long long rekur(int nt, int mt, int xt, int bt) {
  if (n == nt and m == mt) return 1;
  long long &ret = dp[nt][mt][xt][bt];
  if (ret != -1) return ret;
  ret = 0;
  if (xt < a and nt < n) {
    ret = rekur(nt + 1, mt, xt + 1, 0);
  }
  if (bt < b and mt < m) ret += rekur(nt, mt + 1, 0, bt + 1);
  ret %= 100000000;
  return ret;
}
int main() {
  scanf("%d %d %d %d", &n, &m, &a, &b);
  memset(dp, -1, sizeof(dp));
  printf("%lld\n", rekur(0, 0, 0, 0));
}
