#include <iostream> #include <vector> #include <algorithm> using namespace std; int main(){ int n,m; cin >> n >> m; vector<vector<int> > a(n,vector<int>(m,0)); for(int i = 0; i < n; ++ i){ for(int j = 0 ; j < m ; ++ j){ cin >> a[i][j]; } } if(n%2) cout<<n<<endl; else{ int left= 0 ,right =n-1, preRight = n-1; while(left < right){ if(a[left] != a[right]) break; else left++,right--; if(left-1 == right) left = 0,preRight = right; } cout<<preRight+1<<endl; } }