foo.cc: In function 'int main()':
foo.cc:25:12: warning: unused variable 'a1' [-Wunused-variable]
  long long a1=jg2(x1,j1,k);
            ^~
foo.cc:26:12: warning: unused variable 'a2' [-Wunused-variable]
  long long a2=jg2(x2,j2,k);
            ^~
foo.cc:27:12: warning: unused variable 'a3' [-Wunused-variable]
  long long a3=jg2(x3,j3,k);
            ^~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。