我这个小蔡蔡不会优化代码，暴力废了，求助，帮我优化代码。

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;

inline ll read() {
    ll x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

int main() {
    int n = read();
    vector<ll> a(n), b(n), c(n);
    
    for (int i = 0; i < n; i++) a[i] = read();
    for (int i = 0; i < n; i++) b[i] = read();
    for (int i = 0; i < n; i++) c[i] = read();
    
    ll ans = 0;
    vector<ll> sum(n + 1, 0);  
    
    for (int i = 0; i < n; i++) {
        sum[i + 1] = sum[i] + a[i];
    }
    
    for (int l1 = 0; l1 < n; l1++) {
  
        for (int r1 = l1; r1 < n; r1++) {
         
            ll gain1 = 0;
            for (int i = l1; i <= r1; i++) {
                gain1 += b[i] - a[i];
            }
            
         
            for (int l2 = 0; l2 < n; l2++) {
            
                for (int r2 = l2; r2 < n; r2++) {
                    ll curr = sum[n];  
                    
                    curr += gain1;
                    
                    for (int i = l2; i <= r2; i++) {
                        if (i >= l1 && i <= r1) {
                    
                            curr += c[i] - b[i];
                        } else {
                        
                            curr += b[i] - a[i];
                        }
                    }
                    
                    ans = max(ans, curr);
                }
            }
        }
    }
    
    printf("%lld\n", ans);
    return 0;
}