func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = (int)1e6;   const int inf = (int)2e9;   const double eps = 1e-9;   const int mod = (int)1e9 + 7;   int n, l, x, y, a[maxn], ok1, ok2;   map<int, int> was;   bool check(int v) {     if (v >= 0 && v <= l && (was.count(v - x) || was.count(v + x) || ok1) &&         (ok2 || was.count(v - y) || was.count(v + y)))       return true;     return false;   }   int main() {     scanf( %d%d%d%d , &n, &l, &x, &y);     for (int i = 1; i <= n; ++i) {       scanf( %d , &a[i]);       if (was.count(a[i] - x)) ok1 = true;       if (was.count(a[i] - y)) ok2 = true;       was[a[i]] = true;     }     if (ok1 && ok2) {       puts( 0 );       return 0;     }     for (int i = 1; i <= n; ++i) {       if (check(a[i] - x)) {         puts( 1 );         cout << a[i] - x <<   n ;         return 0;       }       if (check(a[i] - y)) {         puts( 1 );         cout << a[i] - y <<   n ;         return 0;       }       if (check(a[i] + x)) {         puts( 1 );         cout << a[i] + x <<   n ;         return 0;       }       if (check(a[i] + y)) {         puts( 1 );         cout << a[i] + y <<   n ;         return 0;       }     }     puts( 2 );     cout << x <<     << y <<   n ;     return 0;   }   