import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string; auto rdsp(){return readln.splitter;} void pick(R,T)(ref R r,ref T t){t=r.front.to!T;r.popFront;} void readV(T...)(ref T t){auto r=rdsp;foreach(ref v;t)pick(r,v);} void readS(T)(size_t n,ref T t){t=new T(n);foreach(ref v;t){auto r=rdsp;foreach(ref j;v.tupleof)pick(r,j);}} void main() { int n; readV(n); struct F { int a, b; } F[] f; readS(n, f); f.sort!"a.a*b.b