from collections import defaultdict

def is_valid(x, y, r, c):
    return x >= 0 and x < r and y >= 0 and y < c

def dfs(grid, start, finish, visited, prob):
    if start == finish:
        return True
    visited[start] = True
    for dx, dy in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
        x, y = start[0] + dx, start[1] + dy
        if is_valid(x, y, len(grid), len(grid[0])):
            if not visited[(x, y)] and grid[x][y] != "#":
                if grid[x][y] == "*":
                    continue
                if grid[x][y].islower():
                    p = prob / 2
                elif grid[x][y].isupper():
                    p = prob
                else:
                    p = prob
                if dfs(grid, (x, y), finish, visited, p):
                    return True
    return False

def find_pairs(grid):
    starts = {}
    finishes = {}
    for i in range(len(grid)):
        for j in range(len(grid[0])):
            if grid[i][j].islower():
                starts[grid[i][j]] = (i, j)
            elif grid[i][j].isupper():
                finishes[grid[i][j]] = (i, j)
    graph = defaultdict(list)
    for start in starts.values():
        visited = defaultdict(bool)
        for finish, pos in finishes.items():
            if dfs(grid, start, pos, visited, 1):
                graph[chr(ord('a')+list(starts.keys()).index(grid[start[0]][start[1]]))].append(chr(ord('A')+list(finishes.keys()).index(grid[pos[0]][pos[1]])))
    nodes = sorted(list(graph.keys()))
    pairs = []
    for i in range(len(nodes)):
        for j in range(i+1, len(nodes)):
            visited = defaultdict(bool)
            if dfs(graph, nodes[i], nodes[j], visited, 1):
                pairs.append(nodes[i] + nodes[j])
    return pairs

t = int(input())
for case in range(1, t+1):
    r, c = map(int, input().split())
    grid = [input().strip() for _ in range(r)]
    pairs = find_pairs(grid)
    if not pairs:
        print(f"Case #{case}: NONE")
    else:
        print(f"Case #{case}: {' '.join(pairs)}")