#include using namespace std; #ifdef LOCAL #include "settings/debug.cpp" #define _GLIBCXX_DEBUG #else #define Debug(...) void(0) #endif using ll = long long; #define rep(i, n) for (int i = 0; i < (n); ++i) int main() { int a, b; cin >> a >> b; constexpr double delta = 1e-7; double ans = 0; for (double l = a; l <= b; l += delta) { double y = (l - a) * (l - b); ans += delta * y; } cout << fixed << setprecision(15) << -ans << endl; return 0; }