#include int abs(int n) { if (n < 0) n *= -1; return n; } int main() { int a, b, c, d; scanf("%d %d %d %d", &a, &b, &c, &d); int ans = 2; if (a == c)ans = 1; if (b == d)ans = 1; if (abs(a - c) + abs(b - d) <= 3)ans = 1; printf("%d\n", ans); return 0; }