F. Gridtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputInputThe input contains 21 lines, each containing 21 characters \texttt{0} or \texttt{1}.ExampleInput
111111101011101111111100000100011001000001101110101101001011101101110101100101011101101110101001001011101100000100111101000001111111101010101111111000000000001100000000111100101111110011101000111010101100110101111101101101001000011001001000001000011000111101110000111001011000000001001001111100111111100001101010000100000100010010100111101110100110110011100101110101100000100010101110101010110000100100000101000011001001111111101011111111100Output
12
 
111111101011101111111100000100011001000001101110101101001011101101110101100101011101101110101001001011101100000100111101000001111111101010101111111000000000001100000000111100101111110011101000111010101100110101111101101101001000011001001000001000011000111101110000111001011000000001001001111100111111100001101010000100000100010010100111101110100110110011100101110101100000100010101110101010110000100100000101000011001001111111101011111111100
12 
['brute force']