#include<bits/stdc++.h>
using namespace std;
#define int long double
int a[1000010];
int sleep_time = 0;
signed main() {
    signed n , x , p , q;
    cin>>n>>x>>p>>q;
    int t = __gcd(p,q);
    p /= t;
    q /= t;
    for(signed i = 0; i< n ; ++i)cin>>a[i];
    sort(a,a+n,greater<int>());
    signed pos = 0;
    signed days = 0;
    while(pos < n) {
        ++days;
        long double must_sleep_time = 
        max( (long double) 1.00 , 
        ceill((long double)( 1.00 * x*p*days)/q - sleep_time));
        long double can_work_time = x - must_sleep_time;
        while(can_work_time >= a[pos] && pos < n)can_work_time -= a[pos++];
        sleep_time += must_sleep_time + can_work_time ;
    }
    cout<<days;
    return 0;
}

预计70pts task1中#5 WA