import std.stdio, std.array, std.string, std.conv, std.algorithm; import std.typecons, std.range, std.random, std.math, std.container; import std.numeric, std.bigint, core.bitop, std.bitmanip; immutable long MOD = 10^^9 + 7; immutable long INF = 1L << 59; void main() { auto N = readln.chomp.to!int; auto X = N.iota.map!(to!real).array; auto Y = readln.split.map!(to!real).array; real E(const real[] A) { return A.sum / N; } real S(const real[] A, real e) { return sqrt(A.map!(a => (a - e) * (a - e)).sum / N); } real Ex = E(X); real Ey = E(Y); real Sx = S(X, Ex); real Sy = S(Y, Ey); real cov = E(N.iota.map!(i => (X[i] - Ex) * (Y[i] - Ey)).array); auto A = cov / (Sx * Sx); auto B = Ey - A * Ex; real ans = N.iota.map!(i => (Y[i] - A * X[i] - B) * (Y[i] - A * X[i] - B)).sum; writefln("%.9f %.9f", B, A); writefln("%.9f", ans); }