/in/foo.cc: In function 'int main()':
/in/foo.cc:9:9: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(a*2+b*2<=c*2)
      ~~~^~~~
/in/foo.cc:9:9: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
/in/foo.cc:9:16: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(a*2+b*2<=c*2)
               ~^~