#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define in insert
#define lb lower_bound
#define F first
#define S second
#define sz size()
#define int long long
#define all(v) v.begin(),v.end()
#define FOR1(x, n) for(int j = x; j <= n; j ++)
#define FOR(x, n, m, d) for(int x = n; x <= m; x += d)
#define FORR(x, n, m, d) for(int x = n; x >= m; x -= d)
#define nikita ios_base::sync_with_stdio(0), cin.tie(0);
const int N = 500+5;
int b[N], a[N][N];
int n,m,k,sum=0,x,y, ans, r,pref[N], cnt, l, mod = 1e9+7, cal,lp = 1;
bool used[N];
void solve(){
cin >> n >> m;
vector<int>v;
k = n/2;
FOR(i, 1, k, 1){
if(n%i==0)v.pb(i);
}
sum = 1e18;
FOR(ok, 0, v.sz-1, 1){
bool hi = 0, f = 0;
ans = 0;
FOR(i, 1, n, 1){
FOR(j, 1, n, 1){
if((j/v[ok])%2 && !hi)ans ++;
}
if((i-1)%v[ok]==0 && i != 1)hi ^= 1;
}
sum = min({sum, ans, n*n-ans});
}
cout << sum;
}
signed main(){
nikita
int tt = 1;
if(!tt)cin >> tt;
FOR(i, 1, tt, 1)solve();
}
