#include <iostream>
#include <vector>
#include <algorithm>
#include <tuple>
using namespace std;

#define REP(i,s,e) for (i = s; i <= e; i++)
#define rep(i,n) REP (i,0,(int)(n)-1)
#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP (i,(int)(n)-1,0)
#define INF (int)1e8
#define MOD (int)(1e9+7)

typedef long long ll;

int par[1000];

int find(int x) {
    if (par[x] == x)
        return x;
    else
        return par[x] = find(par[x]);
}

void unite(int x, int y) {
    par[find(x)] = find(y);
}

int main(void) {
    int N;
    int X[1000], Y[1000];
    cin >> N;
    int i, j;
    rep (i,N) cin >> X[i] >> Y[i];

    vector<tuple<long double,int,int>> len;
    rep (i,N) REP (j,i+1,N-1) {
        long double l = sqrt((long double) (X[i] - X[j]) * (X[i] - X[j]) + (long double) (Y[i] - Y[j]) * (Y[i] - Y[j]));
        len.push_back(make_tuple(l,i,j));
    }
    sort(len.begin(),len.end());
    rep (i,N) par[i] = i;
    for (i = 0; find(0) != find(N-1); i++) {
        unite(get<1>(len[i]),get<2>(len[i]));
    }
    cout << (int)(ceil(get<0>(len[i-1]))+9) / 10 * 10 << endl;
    return 0;
}