/in/foo.cc:12:35: error: 'long long' invalid for 'Matrix'
 long long double Matrix[MAXN][MAXN];
                                   ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:65:33: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=]
    scanf ("%llf", & Matrix[i][j]);
                                 ^