/in/foo.cc: In function 'int read()':
/in/foo.cc:17:41: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  for(;c>='0'&&c<='9';c=getchar()) x=x<<3+x<<1+c-48;
                                        ~^~
/in/foo.cc:17:48: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  for(;c>='0'&&c<='9';c=getchar()) x=x<<3+x<<1+c-48;
                                             ~~~^~~
/in/foo.cc: In function 'void work()':
/in/foo.cc:17:38: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  for(;c>='0'&&c<='9';c=getchar()) x=x<<3+x<<1+c-48;
                                     ~^~~~~
/in/foo.cc:14:6: note: 'x' was declared here
  int x;
      ^
/in/foo.cc:17:38: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  for(;c>='0'&&c<='9';c=getchar()) x=x<<3+x<<1+c-48;
                                     ~^~~~~
/in/foo.cc:14:6: note: 'x' was declared here
  int x;
      ^
/in/foo.cc:17:38: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  for(;c>='0'&&c<='9';c=getchar()) x=x<<3+x<<1+c-48;
                                     ~^~~~~
/in/foo.cc:14:6: note: 'x' was declared here
  int x;
      ^