#include <bits/stdc++.h>

using namespace std;

#define int long long
#define st first
#define dr second

int g1,p1;
int g2,p2;

int ans=0;

int32_t main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  //  freopen("data","r",stdin);
  //  freopen("printer","w",stdout);
    cin>>g1>>p1;
    cin>>g2>>p2;
    for(int w2=0;w2<=10000000;w2++)
    {
        int st=max(p1*g1/100,p2*g2/100-w2);
        int dr=min(g1*p1/100+g1,g2*p2/100+g2-w2)-1;
        if(st<=dr)
        {

            ans=max(ans,w2+dr);
        }
    }
    cout<<ans<<"\n";
    return 0;
}
/**


**/