/in/foo.cc: In function 'void pushdown(int)':
/in/foo.cc:36:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  rev[x]=laz[x]=0;
         ~~~~~~^~
/in/foo.cc: In function 'int build(int, int)':
/in/foo.cc:70:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~