/in/foo.cc: In function 'int main()':
/in/foo.cc:15:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for(int i=0;i<=n;++i) ans2+=n-i>>1;
                               ~^~
/in/foo.cc:17:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for(int i=0;i<=m;++i) ans3+=m-i>>1;
                               ~^~