#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <memory.h>
#include <cassert>

using namespace std;


const int N = 22, NINF = -(1 << 30);
char maze[N][N], res[][15] = { "IMPOSSIBLE", "SUCCESS" };
int n, m, k, v[N][N], dist[N][N];
int dx[] = { -1, 1, 0, 0 };
int dy[] = { 0, 0, -1, 1 };

struct ii {
    int x, y, s;
    ii(void) {}
    ii(int x, int y, int s) : x(x), y(y), s(s) {}
    bool operator<(const ii &o) const {
        if (s == o.s && x != o.x)
            return x > o.x;
        if (s == o.s && x == o.x)
            return y > o.y;
        return s < o.s;
    }
};

bool valid(int nx, int ny) {
    return nx >= 0 && ny >= 0 && nx < n && ny < m;
}

bool bfs(int x, int y) {
    priority_queue <ii> pq; pq.push(ii(x, y, k));
    dist[x][y] = k;
    bool taken = false;
    while (pq.size()) {
        ii co = pq.top(); pq.pop();
        int X = co.x, Y = co.y, S = co.s;
        if (S < 0) continue;
        for (int i = 0; i < 4; ++i) {
            int nx = X + dx[i], ny = Y + dy[i];
            if (valid(nx, ny) && maze[nx][ny] != '#') {
                if (maze[nx][ny] == '.') {
                    if (nx == 1 && ny == 3)
                        printf("that %d, %d\n", X, Y);
                    if (dist[nx][ny] < dist[X][Y]) {
                        dist[nx][ny] = dist[X][Y];
                        pq.push(ii(nx, ny, dist[nx][ny]));
                    }
                } else if (maze[nx][ny] == 's') {
                    if (dist[nx][ny] < dist[X][Y] - 1 && dist[X][Y] - 1 >= 0) {
                        dist[nx][ny] = dist[X][Y] - 1;
                        pq.push(ii(nx, ny, dist[nx][ny]));
                    }
                } else if (maze[nx][ny] == 'x') {
                    if (k - dist[X][Y] <= dist[X][Y])
                        return true;
                    taken = true;
                    //if (dist[X][Y] == 0) return false;
                    if (dist[nx][ny] < dist[X][Y]) {
                        dist[nx][ny] = dist[X][Y];
                        pq.push(ii(nx, ny, dist[nx][ny]));
                    }

                } else if (maze[nx][ny] == '@' && taken) return true;
            }
        }
    }
    return false;
}

int main(void) {
    //freopen("in.txt", "r", stdin);
    scanf("%d %d %d\n", &n, &m, &k);
    int sx, sy, ex, ey, cn = 0;

    for (int i = 0; i < n; i++) {
        scanf("%s", maze[i]);
        for (int j = 0; j < m && cn < 2; j++) {
            switch (maze[i][j]) {
            case '@':
                sx = i, sy = j, ++cn;
                break;
            case 'x':
                ex = i, ey = j, ++cn;
                break;
            }
        }
    }
    memset(dist, -1, sizeof dist);
    printf("%s\n", res[bfs(sx, sy)]);
}