foo.cc: In function 'int main()':
foo.cc:6:13: error: 'x' was not declared in this scope
    6 |     int sum=x-y;
      |             ^
foo.cc:6:15: error: 'y' was not declared in this scope; did you mean 'yn'?
    6 |     int sum=x-y;
      |               ^
      |               yn
foo.cc: At global scope:
foo.cc:11:5: error: redefinition of 'int main()'
   11 | int main()
      |     ^~~~
foo.cc:4:5: note: 'int main()' previously defined here
    4 | int main()
      |     ^~~~
foo.cc: In function 'int main()':
foo.cc:15:7: error: 'jdz' was not declared in this scope
   15 |     s=jdz(a,c)+jdz(b,d);
      |       ^~~

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