from collections import defaultdict

def calculate_distance(graph, start):
    visited = set()
    distance = defaultdict(lambda: float('inf'))
    distance[start] = 0
    queue = [start]
    while queue:
        node = queue.pop(0)
        if node in visited:
            continue
        visited.add(node)
        for neighbor in graph[node]:
            if distance[neighbor] > distance[node] + 1:
                distance[neighbor] = distance[node] + 1
                queue.append(neighbor)
    return distance

def average_distance(W, E):
    distances = []
    for i in range(W):
        for j in range(E):
            # Connect station i on the west side to station j on the east side
            graph = defaultdict(list)
            for k in range(W):
                if k != i:
                    graph['W'+str(k)].append('W'+str(k+1))
                    graph['W'+str(k+1)].append('W'+str(k))
            for k in range(E):
                if k != j:
                    graph['E'+str(k)].append('E'+str(k+1))
                    graph['E'+str(k+1)].append('E'+str(k))
            graph['W'+str(i)].append('E'+str(j))
            graph['E'+str(j)].append('W'+str(i))

            # Calculate distances between all pairs of stations
            total_distance = 0
            for node in graph:
                distance = calculate_distance(graph, node)
                for other_node in graph:
                    if node != other_node:
                        total_distance += distance[other_node]
            distances.append(total_distance / ((W+E)*(W+E-1)/2))
    return distances

# Example usage
W = 2
E = 3
distances = average_distance(W, E)
print(distances)  # prints [1.5, 1.8333, 1.8333, 1.5]