#include using namespace std; using ll = long long; using P = pair; #define fix(x) fixed << setprecision(x) #define asc(x) x, vector, greater #define rep(i, n) for(ll i = 0; i < n; i++) #define all(x) (x).begin(),(x).end() templatebool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;} templatebool chmax(T&a, const T&b){if(a> s; rep(i,1e6){ ll x = (2000 + i) * i; if(x%1000000 == s){ cout << "YES\n"; return 0; } } cout << "NO\n"; return 0; }