foo.cc: In function 'int main()':
foo.cc:37:11: warning: unused variable 'j' [-Wunused-variable]
   37 |     int i,j,k,n,m;
      |           ^
foo.cc:37:13: warning: unused variable 'k' [-Wunused-variable]
   37 |     int i,j,k,n,m;
      |             ^
foo.cc:37:15: warning: unused variable 'n' [-Wunused-variable]
   37 |     int i,j,k,n,m;
      |               ^
foo.cc:37:17: warning: unused variable 'm' [-Wunused-variable]
   37 |     int i,j,k,n,m;
      |                 ^

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