J=lambda:list(map(int,input().split())) N,*_=J() A=[J(),J()] def c(a,d):p=d//a[1];return(a[0]*2+(p-1)*a[2])*a[1]*p//2+d%a[1]*(a[0]+p*a[2]) def D(a): l,r=0,N while l+1>1 if c(a,m)