/in/foo.cc: In function 'int main()':
/in/foo.cc:6:9: warning: right operand of comma operator has no effect [-Wunused-value]
 cin>>a,b;
         ^
/in/foo.cc:7:9: warning: 'b' is used uninitialized in this function [-Wuninitialized]
 cout<<a+b;
         ^