#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const long long int mod = 1e9 + 7;
const double eps = 1e-9;
void solve() {
  int n, m, a, b;
  cin >> n >> m >> a >> b;
  int x1 = (a - 1) / m, y1 = (a - 1) % m, x2 = (b - 1) / m, y2 = (b - 1) % m;
  if (x1 == x2) {
    cout << "1\n";
  } else if (y1 == 0 && (y2 == m - 1 || (x2 * m + y2 == n - 1))) {
    cout << "1\n";
  } else {
    if (y1 == y2 + 1 || y1 == 0 || y2 == m - 1 || (x2 * m + y2 == n - 1) ||
        (x2 - x1) == 1)
      cout << "2\n";
    else
      cout << "3\n";
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int test = 1;
  while (test--) solve();
  return 0;
}
