#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; namespace { using Integer = long long; //__int128; template istream& operator >> (istream& is, pair& p){return is >> p.first >> p.second;} template istream& operator >> (istream& is, vector& vec){for(T& val: vec) is >> val; return is;} template istream& operator , (istream& is, T& val){ return is >> val;} template ostream& operator << (ostream& os, const pair& p){return os << p.first << " " << p.second;} template ostream& operator << (ostream& os, const vector& vec){for(size_t i=0; i ostream& operator , (ostream& os, const T& val){ return os << " " << val;} template void print(const H& head){ cout << head; } template void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); } template void println(const T& ... values){ print(values...); cout << endl; } template void eprint(const H& head){ cerr << head; } template void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); } template void eprintln(const T& ... values){ eprint(values...); cerr << endl; } class range{ Integer start_, end_, step_; public: struct range_iterator{ Integer val, step_; range_iterator(Integer v, Integer step) : val(v), step_(step) {} Integer operator * (){return val;} void operator ++ (){val += step_;} bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;} }; range(Integer len) : start_(0), end_(len), step_(1) {} range(Integer start, Integer end) : start_(start), end_(end), step_(1) {} range(Integer start, Integer end, Integer step) : start_(start), end_(end), step_(step) {} range_iterator begin(){ return range_iterator(start_, step_); } range_iterator end(){ return range_iterator( end_, step_); } }; inline string operator "" _s (const char* str, size_t size){ return move(string(str)); } constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);} constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);} constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); } inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed mt19937 mt(chrono::duration_cast(chrono::steady_clock::now().time_since_epoch()).count()); template string join(const vector& v, const string& sep){ stringstream ss; for(size_t i=0; i0) ss << sep; ss << v[i]; } return ss.str(); } inline string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; } } constexpr long long mod = 9_ten + 7; // A[n*p] * X[p*m] = B[n*m] template vector gaussian_elimination_binary(vector A, vector B, int n, int p, int m){ vector M(n); for(int i=0; i left_most(n,-1); for(int row = 0, col = p+m-1; row=m; col--){ if( ((M[row] >> col) & T(1)) == T(0)){ int pivot = row; for(int row__ = row; row__> col) & T(1)) != T(0) ){ pivot = row__; break; } } if(pivot == row) continue; swap(M[row], M[pivot]); } rank++; left_most[row] = col; for(int row__=row+1; row__> col) & T(1)) != T(0) ) M[row__] ^= M[row]; } row++; } // T = long long //T mask_B = ((T)1<=0; row--){ if( (M[row] & mask_B) != T(0) && (M[row] & mask_A) == T(0) ) has_solution = false; if(left_most[row] == -1) continue; int col = left_most[row]; for(int row__ = row-1; row__>=0; row__--){ if( ((M[row__] >> col) & T(1)) != T(0) ) M[row__] ^= M[row]; } } return has_solution? M : vector(0); } int dx[] = {0, 0, 1,-1, 1, 1,-1,-1}; int dy[] = {1,-1, 0, 0, 1,-1, 1,-1}; #include using bits = bitset<32>; int main(){ int n,m; cin >> n,m; vector> v(n, vector(m)); cin >> v; vector B(n*m); for(int i=0; i A(n*m); for(int i=0; i=n || x<0 || x>=m) continue; A[i*m+j].set(y*m+x); } } } eprintln("A\n", join(A,"\n")); auto res = gaussian_elimination_binary(A,B, n*m, n*m, 1); if(res.size()==0){ println("Impossible"); return 0; } eprintln( join(res, "\n")); int ans = 0; for(int i=0; i> u(n, vector(m)); for(int i=0; i=n || x<0 || x>=m) continue; u[y][x] ^= 1; } } } for(int i=0; i