a,b,n,m=map(int,input().split())
ans=0
ans+=min(a,b)
if min(a,b)==a:
    b-=a
    ans+=b//(m+1)
    print(ans)
    exit()
if min(a,b)==b:
    a-=b
    ans+=a//(n+1)
    print(ans)