#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i, n) for (int (i) = 0; (i) < (n); (i)++) #define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++) #define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--) #define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--) #define DEBUG(C) cerr << #C << " = " << C << endl; using LL = long long; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; using VD = vector; using VVD = vector; using PII = pair; using PDD = pair; using PLL = pair; using VPII = vector; template using VT = vector; #define ALL(a) begin((a)), end((a)) #define RALL(a) rbegin((a)), rend((a)) #define SORT(a) sort(ALL((a))) #define RSORT(a) sort(RALL((a))) #define REVERSE(a) reverse(ALL((a))) #define MP make_pair #define FORE(a, b) for (auto &&a : (b)) #define FIND(s, e) ((s).find(e) != (s).end()) #define EB emplace_back const int INF = 1e9; const int MOD = INF + 7; const LL LLINF = 1e18; int H, W; VVI v; VT> vis; const int vh[] = {0, 0, -1, 1}; const int vw[] = {-1, 1, 0, 0}; bool inside(int h, int w) { return 0 <= h && h < H && 0 <= w && w < W; } int main(void) { scanf("%d%d", &W, &H); vis.resize(H, VT(W, false)); v.resize(H, VI(W)); REP(i, H) REP(j, W) { scanf("%d", &v[i][j]); } queue> q;//(now, prev) bool f = false; REP(i, H) REP(j, W) if (!vis[i][j]) { const int num = v[i][j]; q.push(MP(MP(i, j), MP(-1, -1))); vis[i][j] = true; while (!q.empty()) { auto now = q.front().first; auto prev = q.front().second; q.pop(); REP(i, 4) { const int nh = now.first + vh[i]; const int nw = now.second + vw[i]; if (!inside(nh, nw)) continue; if (v[nh][nw] != num) continue; //cout << now.first << " " << now.second << " " << nh << " " << nw << " " << v[nh][nw] << endl; if (vis[nh][nw]) { if (MP(nh, nw) == prev) continue; f = true; cout << nh << " " << nw << endl; goto last; } else vis[nh][nw] = true; q.push(MP(MP(nh, nw), now)); } } } last: cout << (f ? "Possible" : "Impossible") << endl; }