#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<int> x(n), y(n);
    for(int i=0; i<n; ++i)
        cin >> x[i] >> y[i];

    multimap<int, int> mm;
    vector<int> dp(n, INT_MAX);
    mm.insert(make_pair(0, 0));
    dp[0] = 0;
    while(!mm.empty()){
        int len, pos;
        tie(len, pos) = *mm.begin();
        mm.erase(mm.begin());
        if(dp[pos] < len)
            continue;

        for(int i=0; i<n; ++i){
            long long dx = x[pos] - x[i];
            long long dy = y[pos] - y[i];
            long long dist = dx * dx + dy * dy;

            int len2 = (int)sqrt(dist);
            if(len2 * (long long)len2 < dist)
                ++ len2;

            len2 = max(len2, len);
            if(len2 < dp[i]){
                mm.insert(make_pair(len2, i));
                dp[i] = len2;
            }
        }
    }

    int ans = (dp[n-1] + 9) / 10 * 10;
    cout << ans << endl;

    return 0;
}