#include using namespace std; #define rep(i,n) for(int i=0;i=0;--i) #define debug(output) if(debugFlag)cout<<#output<<"= "< P; const bool debugFlag=true; const lint linf=1.1e18;const int inf=1.01e9; constexpr int MOD=1000000007; templatebool chmax(T &a, const T &b) { if(a < b){ a = b; return 1; } return 0; } templatebool chmin(T &a, const T &b) { if(a > b){ a = b; return 1; } return 0; } #include using namespace atcoder; using mint = modint1000000007; signed main(){ lint s;cin>>s; rep1(i,1000050){ if(i*i%1000000==s){ cout<<"YES"<<"\n"; return 0; } } cout<<"NO"<<"\n"; return 0; }