foo.cc: In function 'int main()':
foo.cc:6:17: warning: unused variable 'a1' [-Wunused-variable]
    6 |     long long n,a1=1,c1=1,k=0,s=0,b1=1;
      |                 ^~
foo.cc:6:22: warning: unused variable 'c1' [-Wunused-variable]
    6 |     long long n,a1=1,c1=1,k=0,s=0,b1=1;
      |                      ^~
foo.cc:6:35: warning: unused variable 'b1' [-Wunused-variable]
    6 |     long long n,a1=1,c1=1,k=0,s=0,b1=1;
      |                                   ^~

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