#include #include #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") using namespace std; using namespace atcoder; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repll(i, n) for (long long i = 0; i < (long long)(n); i++) #define rep2(i, n, m) for (int i = n; i < (int)(m); i++) #define repll2(i, n, m) for (long long i = n; i < (long long)(m); i++) #define all(v) v.begin(),v.end() using ll=long long; using ld=long double; using vi=vector; using vvi=vector; using vvvi=vector; using vl=vector; using vvl=vector; using vvvl=vector; using vld=vector; using vvld=vector; int dx[8]={1,0,-1,0,1,1,-1,-1}; int dy[8]={0,1,0,-1,1,-1,1,-1}; const double PI = acos(-1); //const ll MOD=1e9+7; //const ll MOD=998244353; const ll INF=(1LL<<60); const int INF2=(1<<30); //using mint=modint1000000007; //using mint=modint998244353; int main() { ios::sync_with_stdio(false); std::cin.tie(nullptr); int n;cin>>n; int op[n][n]; rep(i,n)rep(j,n)cin>>op[i][j]; int e=-1; set st; //単位元 rep(i,n){ int f=1; rep(j,n)if(op[i][j]!=j||op[j][i]!=j)f=0; if(f){ e=i; st.insert(e); } } if(e==-1){ cout<<"No"<