foo.cc: In function 'int main()':
foo.cc:7:2: error: expected ';' before 'in'
  in>>a>>b>>c;
  ^~
foo.cc:7:13: warning: statement has no effect [-Wunused-value]
  in>>a>>b>>c;
             ^
foo.cc:8:6: warning: unused variable 'a1' [-Wunused-variable]
  int a1=a,b1=b,c1=c;
      ^~

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