#include using namespace std; #define verify(f) {if(not(f)) {cerr<<#f<>r>>c); verify(1<=r and r<=2000); verify(1<=c and c<=2000); for (int i=0; i>s); verify(s.size()==c); for (auto const &j: s){ verify('a'<=j and j<='z'); } } int n,m; verify(cin>>n>>m); verify(r<=n and n<=2000); verify(c<=m and m<=2000); for (int i=0; i>s); verify(s.size()==m); for (auto const &j: s){ verify('a'<=j and j<='z'); } } { string s; verify(not (cin>>s)); } verify(cin.eof()); return 42; }