#include <bits/stdc++.h>
const int con = 100000000;
int main() {
  int n, i, k, j, p, a, b, a1, b1, q[101][101][21], r;
  while (scanf("%d%d%d%d", &a, &b, &a1, &b1) != EOF) {
    for (i = 0; i <= a; i++)
      for (j = 0; j <= b; j++)
        for (k = 0; k <= 20; k++) q[i][j][k] = 0;
    for (i = 1; i <= a1; i++) q[i][0][i] = 1;
    for (i = 1; i <= b1; i++) q[0][i][i + 10] = 1;
    for (i = 1; i <= a; i++)
      for (j = 1; j <= b; j++) {
        for (k = 11; k <= b1 + 10; k++) q[i][j][1] += q[i - 1][j][k];
        q[i][j][1] %= con;
        for (k = 2; k <= a1; k++) q[i][j][k] = q[i - 1][j][k - 1];
        for (k = 1; k <= a1; k++) q[i][j][11] += q[i][j - 1][k];
        q[i][j][11] %= con;
        for (k = 12; k <= b1 + 10; k++) q[i][j][k] = q[i][j - 1][k - 1];
      }
    r = 0;
    for (k = 1; k <= 20; k++) r += q[a][b][k];
    r %= con;
    printf("%d\n", r);
  }
  return 0;
}
