#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

#define MAX_HEIGHT 20
#define MAX_WIDTH 1000
#define FLAP 4

char grid[MAX_HEIGHT + 1][MAX_WIDTH + 1];
int H, W, score;

bool AI(int x, int y, int speed)
{
    if (grid[x][y] == '#' || x >= H || y >= W)
    {
        score = max(score, y);
        return false;
    }
    score = max(score, y);
    int afterFlap = (x - FLAP<0) ? 0 : x - FLAP;
    int afterStay = x + (++speed);
    if (AI(afterFlap, y + 1, 0) || AI(afterStay, y + 1, speed))
    {
        return true;
    }
    return false;
}

int main() {
    int C, start;
    scanf("%d", &C);
    while (C != 0)
    {
        --C;
        scanf("%d%d", &H, &W);
        for (int i = 0; i < H; ++i)
        {
            scanf("%s", grid[i]);
        }
        for (int i = 0; i < H; ++i)
        {
            if (grid[i][0] == '@') start = i;
        }
        AI(start, 0, 0);
        printf("%d\n", score);
        score = 0;
        memset(grid, 0, sizeof(grid));
    }
    return 0;
}