foo.cc: In function 'int main()':
foo.cc:11:4: error: 'k' was not declared in this scope
   11 |    k++;
      |    ^
foo.cc:12:11: warning: too many arguments for format [-Wformat-extra-args]
   12 |    printf("-4d",i);
      |           ^~~~~
foo.cc:17:8: error: 'sum' was not declared in this scope
   17 |  cout<<sum;
      |        ^~~

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