#include using namespace std; using LL = long long int; #define incID(i, l, r) for(int i = (l) ; i < (r); ++i) #define incII(i, l, r) for(int i = (l) ; i <= (r); ++i) #define decID(i, l, r) for(int i = (r) - 1; i >= (l); --i) #define decII(i, l, r) for(int i = (r) ; i >= (l); --i) #define inc(i, n) incID(i, 0, n) #define inc1(i, n) incII(i, 1, n) #define dec(i, n) decID(i, 0, n) #define dec1(i, n) decII(i, 1, n) #define inID(v, l, r) ((l) <= (v) && (v) < (r)) #define inII(v, l, r) ((l) <= (v) && (v) <= (r)) #define PB push_back #define EB emplace_back #define MP make_pair #define FI first #define SE second #define ALL(v) v.begin(), v.end() #define RALL(v) v.rbegin(), v.rend() auto setmin = [](auto & a, auto b) { return (b < a ? a = b, true : false); }; auto setmax = [](auto & a, auto b) { return (b > a ? a = b, true : false); }; auto setmineq = [](auto & a, auto b) { return (b <= a ? a = b, true : false); }; auto setmaxeq = [](auto & a, auto b) { return (b >= a ? a = b, true : false); }; auto fl = [](auto a, auto b) { assert(b != 0); return a / b - (a % b != 0 && ((a >= 0) != (b >= 0)) ? 1 : 0); }; auto ce = [](auto a, auto b) { assert(b != 0); return a / b + (a % b != 0 && ((a >= 0) == (b >= 0)) ? 1 : 0); }; auto mo = [](auto a, auto b) { assert(b != 0); a %= b; if(a < 0) { a += abs(b); } return a; }; LL gcd(LL a, LL b) { return (b == 0 ? a : gcd(b, a % b)); } LL lcm(LL a, LL b) { return a / gcd(a, b) * b; } #define bit(b, i) (((b) >> (i)) & 1) #define SI(v) static_cast(v.size()) #define RF(e, v) for(auto & e: v) #define until(e) while(! (e)) #define if_not(e) if(! (e)) #define ef else if #define UR assert(false) // ---- ---- using LD = long double; int main() { LL a, b, c, d; cin >> a >> b >> c; d = b * b - 4 * a * c; LD A = a, B = b, C = c, D = d; multiset ans; if(a != 0) { if(d < 0) { } if(d == 0) { ans.insert(-B / (2 * A)); } if(d > 0) { auto f = [&](LD x) -> LD { return a * x * x + b * x + c; }; auto fd = [&](LD x) -> LD { return 2 * a * x + b; }; LD x0 = -(B + sqrt(D)) / (2 * A); LD x1 = -(2 * C) / (B + sqrt(D)); inc(i, 3) { x0 -= f(x0) / fd(x0); x1 -= f(x1) / fd(x1); } ans.insert(x0); ans.insert(x1); } } ef(b != 0) { ans.insert(-C / B); } ef(c != 0) { } else { cout << -1 << endl; return 0; } cout << SI(ans) << endl; RF(e, ans) { printf("%.15Lf\n", e); } return 0; }