import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); }
void log()(){ writeln(""); } void log(T, A ...)(T t, lazy A a){ if(DEBUG) write(t, " "), log(a); } bool DEBUG = 0; 
string rstring(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
T rtype(T)(){ return rstring.to!T; } alias rint = rtype!int, rlong = rtype!long, rreal = rtype!real;
T[] rtypes(T)(int n){ return n.iota.map!(i => rtype!T()).array; } alias rint = rtypes!int, rlong = rtypes!long, rreal = rtypes!real;
T[][] rtypess(T)(int n, int m){ return n.iota.map!(i => rtypes!T(m)).array; } alias rint = rtypess!int, rlong = rtypess!long, rreal = rtypess!real;

// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
	int n = rint;
	long k = rlong;
	long[] as = rlong(n);
	long[] fs = rlong(n);
	
	log("n:", n, "k:", k, "as:", as, "fs:", fs);
	
	long xsum = as.sum - k;
	if(xsum < 0) xsum = 0;
	
	log("xsum:", xsum);
	
	real q = xsum / fs.map!(f => 1.0 / f.to!real).sum;
	
	log("q:", q);
	
	long[] xs, us;
	long ans;
	foreach(f; fs){
		long x = (q / f.to!real).to!long;
		xs ~= x, us ~= (x + 1) * f;
		ans = max(ans, x * f);
	}
	us.sort();
	
	log("xs:", xs, "us:", us);
	
	long r = xsum - xs.sum;
	
	log("r:", r);
	
	us.sort();
	foreach(u; us[0 .. r]) ans = max(ans, u);
	
	ans.writeln;
}
