foo.cc: In function 'int main()':
foo.cc:87:7: warning: unused variable 'j' [-Wunused-variable]
   87 | int i,j,a,b;char cc;
      |       ^
foo.cc:90:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   90 | scanf("%d%d",&n,&m);
      | ~~~~~^~~~~~~~~~~~~~

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