foo.cc: In function 'int main()':
foo.cc:5:14: warning: unused variable 'sb' [-Wunused-variable]
    5 |  int a,b,c,x,sb=0,u,a1,b2,c2;
      |              ^~
foo.cc:23:8: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
   23 |  system("pause");
      |  ~~~~~~^~~~~~~~~

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