/in/foo.cc: In function 'int main()':
/in/foo.cc:26:28: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   q1=f[i][j-1],q2=f[i+(1<<j-1)][j-1],f[i][j]=q2<q1?q1:q2;
                           ~^~