1```csharp
2using System;
3using System.Collections.Generic;
4
5public class ParallelCourses {
6    public static int MinTime(int n, int[][] relations, int[] time) {
7        var adj = new List<int>[n + 1];
8        var indegree = new int[n + 1];
9        var dp = new int[n + 1];
10
11        for (int i = 0; i <= n; i++)
12            adj[i] = new List<int>();
13
14        foreach (var relation in relations) {
            int u = relation[0], v = relation[1];
            adj[u].Add(v);
            indegree[v]++;
        }

        var queue = new Queue<int>();
        for (int i = 1; i <= n; i++) {
            if (indegree[i] == 0) {
                queue.Enqueue(i);
                dp[i] = time[i - 1];
            }
        }

        while (queue.Count > 0) {
            int u = queue.Dequeue();
            foreach (var v in adj[u]) {
                dp[v] = Math.Max(dp[v], dp[u] + time[v - 1]);
                indegree[v]--;
                if (indegree[v] == 0) {
                    queue.Enqueue(v);
                }
            }
        }

        int maxTime = 0;
        for (int i = 1; i <= n; i++)
            maxTime = Math.Max(maxTime, dp[i]);

        return maxTime;
    }

    public static void Main() {
        int n = 5;
        int[][] relations = new int[][] { new int[] { 1,5 }, new int[] { 2,5 }, new int[] { 3,5 }, new int[] { 3,4 }, new int[] { 4,5 } };
        int[] time = new int[] { 1, 2, 3, 4, 5 };
        Console.WriteLine(MinTime(n, relations, time)); // Output: 12
    }
}
```

```