#include using namespace std; using ll = unsigned long long; using ld = long double; bool hantei(ll A,ll B,ll X){ if(A*B<((X*X-A-B)/2)*((X*X-A-B)/2))return true; return false; } ll x(ll A,ll B){ //4AB<(X^2-A-B)^2となるような、最小のX ll l = 1;//ng ll r = A*B+A+B;//ok while(r-l>1){ ll mid = (l+r)/2; if(hantei(A,B,mid))r = mid; else l = mid; } return r; } int main(){ ll N;cin >> N; //A+B+2√AB> A >> B; cout << x(A,B) << endl; } }