#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cstdlib>

 #include<cmath>

 #define lson l, m, rt<<1

 #define rson m+1, r, rt<<1|1

 #define IO ios::sync_with_stdio(false);cin.tie(0);

 #define INF 1e9

 typedef long long ll;

 using namespace std;

 int n, m;

 ll dp[][];

 typedef struct {

     ll x, c;

 }Node;

 Node node[];

 bool cmp(const Node a, const Node b)

 {

     return a.x<b.x;

 }

 int main()

 {

     while(cin >> n){

         for(int i = ; i <= n; i++){

             cin >> node[i].x >> node[i].c;

         }

         for(int i = ; i <= n; i++){

             dp[i][] = INF;

             dp[i][] = INF;

         }

         dp[][]=;dp[][]=;

         sort(node+, node+n+, cmp);

         for(int i = ; i <= n; i++){

             dp[i][] = min(dp[i-][], dp[i-][])+node[i].c;

             ll tmp = ;

             for(int j = i-; j >= ; j--){

                 tmp += (i-j)*(node[j+].x - node[j].x);//次数*长度

                 dp[i][] = min(dp[i][], dp[j][]+tmp);

             }

         }

         cout << min(dp[n][], dp[n][]) << endl;

     }

     return ;

 }