#include <functional>
#include <algorithm>
#include <iostream>
#include <stdint.h>
#include <numeric>
#include <utility>
#include <sstream>
#include <iomanip>
#include <cstdlib>
#include <cstring>
#include <complex>
#include <cassert>
#include <climits>
#include <cstdio>
#include <cctype>
#include <vector>
#include <bitset>
#include <string>
#include <ctime>
#include <deque>
#include <stack>
#include <cmath>
#include <queue>
#include <list>
#include <map>
#include <set>
using namespace std;

const int N = 22;
char maze[N][N], res[][15] = { "IMPOSSIBLE", "SUCCESS" };
int n, m, k, dist[N][N][444], v[N][N];
int dx[] = { -1, 1, 0, 0 };
int dy[] = { 0, 0, -1, 1 };

struct ii {
    int x, y, s;
    ii(int x, int y, int s) : x(x), y(y), s(s) {}
};

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

bool bfs(int x, int y) {
    queue <ii> q; q.push(ii(x, y, k));
    dist[x][y][k] = 0;
    bool flag = false;
    int after = -1;
    while (!q.empty()) {
        ii cur = q.front(); q.pop();
        int X = cur.x, Y = cur.y, S = cur.s;
        v[X][Y] = 1;
        if (~after) S = after;
        for (int i = 0; i < 4; i++) {
            int nx = X + dx[i], ny = Y + dy[i];
            if (valid(nx, ny) && maze[nx][ny] != '#') {
                if (v[nx][ny] && !flag) continue;
                if (maze[nx][ny] == '.') {
                    dist[nx][ny][S] = dist[X][Y][S] + 1;
                    q.push(ii(nx, ny, S));
                } else if (maze[nx][ny] == 's' &&  S - 1 >= 0) {
                    if (~after) --after;
                    dist[nx][ny][S - 1] = dist[X][Y][S] + 1;
                    q.push(ii(nx, ny, S - 1));
                } else if (maze[nx][ny] == 'x') {
                    dist[nx][ny][S] = dist[X][Y][S] + 1;
                    flag = true;
                    after = S;
                    q.push(ii(nx, ny, S));
                } else if (maze[nx][ny] == '@' && flag)
                    return true;
            }
        }
    }
    return false;
}

int main(void) {
    //freopen("in.txt", "r", stdin);
    scanf("%d %d %d", &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;
            }
        }
    }
    puts(res[bfs(sx, sy)]);
}