C - Greedy Arkady-（贪心思维题-）

C - Greedy Arkady

 CodeForces - 965C 

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,m,k,d;
ll l;
ll ans;
int main()
{
    cin>>n>>k>>m>>d;
    for(int y=1; y<=d; y++)
    {
        ll x=n/(k*y-k+1);
        if(!x)break;
        if(x>m)x=m;
        ans=max(ans,x*y);
    }
    cout<<ans;
    return 0;
}