/in/foo.cc: In function 'matrix pow(matrix, long long int, long long int)':
/in/foo.cc:37:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
   if(q&1) if(fl) res=res*w; else res=w,fl=1;
     ^
/in/foo.cc: In function 'matrix operator*(matrix, matrix)':
/in/foo.cc:32:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^