#ifndef INCLUDED_MAIN #define INCLUDED_MAIN #include __FILE__ vector<ll> dx={-1,0,1}; vector<ll> dy={-1,0,1}; int main(){ // squareだね ll n; cin>>n; ll ok=0; ll ng=n; while(ng-ok>1) { ll mid=(ng-ok)/2+ok; if(mid*mid<=n) ok=mid; else ng=mid; } cout<<ok<<endl; } #else #include <bits/stdc++.h> using namespace std; #define rep(i,n) for(int i=0;i<n;i++) #define srep(i,l,r) for(int i=l;i<=r;i++) using ll = long long; #define mod 998244353ll #define vout(v) for(auto i :v) cout<<i<<" "; #define INF 922330000000000000ll #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define enld endl #define Rn return #define vl vector<ll> bool isin(ll i,ll j,ll hgt,ll width) { if(i<0 || i>=hgt || j<0 || j>=width) return false; else return true; } ll lensum(ll l,ll r) { ll len=r-l+1; return (l-1)*len + (r-l+1)*(r-l+1)/2; } vector<ll> Erasieve(ll n) { vector<bool> is_prime(n+1, true); is_prime[0] = is_prime[1] = false; for (int i=2;i*i<=n;++i) { if (is_prime[i]) { for (int j=i*i;j<=n;j+=i) is_prime[j] = false; } } vector<ll> primes; srep(i,2,n) { if (is_prime[i]) primes.push_back(i); } return primes; } ll divcount(ll n) { ll ans=0; for(int i=1;i*i<=n;i++) { if(n%i==0) ans+=(i*i==n ? 1:2); } return ans; } struct UnionFind { vector<int> par; vector<int> rank; UnionFind(int N) : par(N), rank(N, 0) { for (int i = 0; i < N; i++) { par[i] = i; } } // 経路圧縮 int root(int x) { if (par[x] == x) return x; return par[x] = root(par[x]); } void unite(int x, int y) { int rx = root(x); int ry = root(y); if (rx == ry) return; if (rank[rx] < rank[ry]) { par[rx] = ry; } else { par[ry] = rx; if (rank[rx] == rank[ry]) { rank[rx]++; } } } bool same(int x, int y) { return root(x) == root(y); } }; template <class T> void vecpr(T first,T last) { ll tmp=0; for(auto it=first;it!=last;++it) { if(tmp) cout<<" "; cout<<*it; tmp++; } cout<<endl; } template <class T> void vvpr(vector<vector<T>> a) { for(int i=0;i<(ll)a.size();i++) { for(int j=0;j<(ll)a[i].size();j++) { if(j) cout<<" "; cout<<a[i][j]; } cout<<endl; } } vector<ll> slmax(vector<ll> a, ll limit, ll breadth) {//slidewindowによる幅breadthでの区間最大値評価,limit=a.size() deque<ll> deq; vector<ll> max_numbers(limit, (-1)*INF); rep(i, limit) { while (!deq.empty() && deq.front() <= i - breadth) deq.pop_front(); while (!deq.empty() && a[deq.back()] <= a[i]) deq.pop_back(); deq.push_back(i); max_numbers[i] = a[deq.front()]; } return max_numbers; } vector<ll> slmin(vector<ll> a, ll limit, ll breadth) {//slidewindowによる幅breadthでの区間最小値評価,limit=a.size() deque<ll> deq; vector<ll> min_numbers(limit, INF); rep(i, limit) { while (!deq.empty() && deq.front() <= i - breadth) deq.pop_front(); while (!deq.empty() && a[deq.back()] >= a[i]) deq.pop_back(); deq.push_back(i); min_numbers[i] = a[deq.front()]; } return min_numbers; } ll modpow(ll fl,ll po,ll mode) { //mode0=modなし、mode1=あり ll ret=1; rep(i,po) { ret*=fl; if(mode) ret=(ret+mod)%mod; } return ret; } ll gcd(ll a,ll b) { //Euclid if(a<b) return gcd(b,a); if(a%b==0) return b; return gcd(b,a%b); } vector<ll> lis_min(vector<ll> &a) { //最後まで見たときに、「長さiの最後尾は最小でいくつか?」を返す ll n=(ll)a.size(); vector<ll> dp(n,INF); rep(i,n){ auto itr = lower_bound(dp.begin(),dp.end(), a[i]); *itr = a[i]; } return dp; }//あんま使えない void lis_min_update(vector<ll>& dp, ll x) { //↑を一回ごとに処理するやつ (cf.abc393-f); auto it=lower_bound(dp.begin(), dp.end(), x); if(it==dp.end()) dp.push_back(x); else *it=x; } vector<ll> lis_size(vector<ll>& a ,vector<ll>&seqcopy) { // 最長増加部分列の a index目までみた時点の長さがdp[i] ll n=a.size(); vector<ll> dp(n,1); vector<ll> seq; rep(i,n) { auto it=lower_bound(seq.begin(), seq.end(), a[i]); if (it==seq.end()) seq.push_back(a[i]); else *it=a[i]; dp[i]=distance(seq.begin(), lower_bound(seq.begin(), seq.end(), a[i]))+1; } srep(i,1,n-1) { if(dp[i]<dp[i-1]) dp[i]=dp[i-1]; } seqcopy=seq; return dp; } #endif