Pilots Bottom-up

#include <bits/stdc++.h>
#define f(i,a,b) for(int i = (a); i <= (b); i++)
using namespace std;

const int INF = 2000000007;
int A[10005], B[10005], DP[5005][5005], N;

int main()
{
    cin >> N;
    int ans = 0;
    f(i,1,N) cin >> A[i] >> B[i];
    f(i,0,N/2) f(j,0,N/2) DP[i][j] = INF;
    DP[0][0] = 0;
    f(j,0,N/2) f(i,0,j)
    {
        DP[i+1][j] = min(DP[i+1][j], DP[i][j] + A[i+j+1]);
        DP[i][j+1] = min(DP[i][j+1], DP[i][j] + B[i+j+1]);
    }
    cout << DP[N/2][N/2];
}