https://www.nowcoder.com/acm/contest/170/B

var
    a:array[1..300,1..300]of char;
    f:array[1..300]of string;
    n,m,q,i,j,len,minp,x,y:longint;
begin
    readln(n,m,q);
    for i:=1 to n do
    begin
      for j:=1 to m do
        read(a[i,j]);
      readln;
    end;
    for i:=1 to q do
    begin
      readln(x,y);
      len:=0;
      f[1]:='';
      while (x+len<=n)and(y+len<=m) do
      begin
        f[1]:=f[1]+a[x+len,y+len];
        inc(len);
      end;
      for j:=2 to len do
      begin
        f[j]:=f[j-1]+f[j-1][1];
        delete(f[j],1,1);
      end;
      minp:=1;
      for j:=2 to len do
        if f[j]<f[minp] then
          minp:=j;
      writeln(f[minp]);
    end;
end.