#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#define fi first
#define se second
#define ll long long
#define pb push_back
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
int n = (int)s.size();
long long dp[(1<<n)][n];
for (int i = 0; i < (1<<n); ++i)
{
for (int j = 0; j < n; ++j)
{
dp[i][j]=1e18;
}
}
for (int i = 0; i < n; ++i)
{
dp[(1<<i)][i]=0;
}
for (int mask = 1; mask < (1<<n); ++mask)
{
for (int i = 0; i < n; ++i)
{
if((1<<i)&mask){
int submask=mask-(1<<i);
for (int j = 0; j < n; ++j)
{
if((1<<j)&submask){
dp[mask][i]=min(dp[mask][i],dp[submask][j]+max(0,t[j]-s[i]));
}
}
}
}
}
long long ans=1e18;
for (int i = 0; i < n; ++i)
{
ans=min(ans,dp[(1<<n)-1][i]);
}
return ans;
}
/*int main(){
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int n;
assert(1 == scanf("%d", &n));
std::vector<int> s(n), t(n);
for (int i = 0; i < n; ++i)
assert(2 == scanf("%d%d", &s[i], &t[i]));
long long ans = plan_roller_coaster(s, t);
printf("%lld\n", ans);
return 0;
}*/
