foo.cc: In function 'int main()':
foo.cc:6:11: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>a,b,c;
           ^
foo.cc:6:12: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>a,b,c;
            ^
foo.cc:7:9: warning: 'b' is used uninitialized in this function [-Wuninitialized]
  cout<<a+b+c<<endl; 
        ~^~
foo.cc:7:12: warning: 'c' is used uninitialized in this function [-Wuninitialized]
  cout<<a+b+c<<endl; 
            ^

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