#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
#define ii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
struct dsu {
vector <int> par;
void init(int n){
par.assign(n, 0);
for (int i = 0; i < n; ++i) par[i] = i;
}
int findset(int u) {
if(par[u] == u) return u;
return par[u] = findset(par[u]);
}
bool mergeset(int u, int v) {
u = findset(u), v = findset(v);
if(u == v) return false;
par[v] = u; return true;
}
} pa;
long long plan_roller_coaster(vector<int> s, vector<int> t) {
int n = s.size();
vector <ii> vals;
int all_mask = 1ll << n;
int64_t inf = 1e18;
vector <vector<long long>> dp(all_mask, vector<long long>(n+1, inf));
for (int i = 0; i < n; ++i) {
dp[1 << i][i] = 0;
}
vector<ii> order_mask;
for (int i = 2; i < all_mask; ++i) {
order_mask.eb(__builtin_popcount(i), i);
}
sort(begin(order_mask), end(order_mask));
for (ii &_ : order_mask) {
int mask = _.se;
for (int i = 0; i < n; ++i) {
if(mask >> i & 1) {
int pre = mask ^ (1ll << i);
for (int j = 0; j < n; ++j) {
if(pre >> j & 1) {
dp[mask][i] = min(dp[mask][i], dp[pre][j] + 1ll * max(0, t[i] - s[j]));
}
}
}
}
}
long long ans = inf;
for (int i = 0; i < n; ++i) ans = min(ans, dp[all_mask - 1][i]);
return ans;
}
#ifdef LOCAL
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
freopen("in.txt", "r", stdin);
int n; cin >> n;
vector <int> s(n), t(n);
for (int i = 0; i < n; ++i) {
cin >> s[i] >> t[i];
}
cout << plan_roller_coaster(s, t);
}
#endif //LOCAL
