foo.cc: In function 'int main()':
foo.cc:8:14: warning: unused variable 'a1' [-Wunused-variable]
    8 |  long long n,a1=1,c1=1,k=0,s=0,b1=1;
      |              ^~
foo.cc:8:19: warning: unused variable 'c1' [-Wunused-variable]
    8 |  long long n,a1=1,c1=1,k=0,s=0,b1=1;
      |                   ^~

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