include
include
include
define Maxsize 1001
using namespace std;
int main()
{
int a[Maxsize][Maxsize] = {0};
int n, m, r, c;
cin >> n >> m >> r >> c;
int n1=1, n2=n, m1=1, m2=m;
int x = 1, y = 1, sum = 1;
while (sum <= n * m)
{
while (sum<= n * m && y < m2)
{
a[x][y] = sum++;
y++;
}
while (sum <= n * m && x < n2) { a[x][y] = sum++; x++; } while (sum <= n * m && y > m1) { a[x][y] = sum++; y--; } while (sum <= n * m && x > n1) { a[x][y] = sum++; x--; } n1++; n2--; m1++; m2--; x++; y++; if (sum == n * m) a[x][y] == sum++; } if (m == n && m % 2 == 1) a[m / 2 + 1][m / 2 + 1] = n * m; cout << a[r][c]; return 0;
}