#include <bits/stdc++.h>
#define endl "\n"
#define pb push_back
#define int long long
using namespace std;
const int inf = 2e18 + 5;
const int N = 2e5 + 5;
const int mod = 1e9 + 7;
int32_t main(){
//freopen("in.txt","r", stdin);
int n;
cin>>n;
vector<array<int, 2> > a(n);
for(int i = 0; i < n; i++){
cin>>a[i][0]>>a[i][1];
}
vector<vector<vector<int> > > go(500, vector<vector<int> >(500, vector<int>(2)));
int sum = 0, mxx = 0, mxy = 0;
for(int i = 0; i < n; i++){
int x = a[i][0], y = a[i][1];
sum = (sum + x + y);
mxx = max(mxx, x);
mxy = max(mxy, y);
while(x > 0 || y > 0){
if(x == 0){
go[x][y-1][1]++;
y--;
}
else if(y == 0){
go[x-1][y][0]++;
x--;
}
else if((x-1)&y){
go[x][y-1][1]++;
y--;
}
else{
go[x-1][y][0]++;
x--;
}
}
}
int ans = sum;
queue<array<int, 3> > q;
q.push({0, 0, sum});
while(!q.empty()){
int x = q.front()[0], y = q.front()[1], val = q.front()[2];
q.pop();
ans = min(ans, val);
if(!((x+1)&y) && x < mxx){
q.push({x+1, y, val - go[x][y][0] + (n - go[x][y][0])});
}
if(!(x&(y+1)) && y < mxy){
q.push({x, y+1, val - go[x][y][1] + (n - go[x][y][1])});
}
}
cout<<ans<<endl;
return 0;
}
