foo.cc: In function 'int main()':
foo.cc:4:21: warning: unused variable 'f' [-Wunused-variable]
    4 |     int sum=0,n,b,c,f;
      |                     ^
foo.cc:17:11: error: expected '}' at end of input
   17 |  cout<<sum;
      |           ^
foo.cc:3:11: note: to match this '{'
    3 | int main(){
      |           ^

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