foo.cc: In function 'int main()':
foo.cc:6:24: warning: unused variable 's' [-Wunused-variable]
    6 |  int n,t,a,b,f,y=0,z=0,s=0;
      |                        ^
foo.cc:29:3: warning: 'f' may be used uninitialized in this function [-Wmaybe-uninitialized]
   29 |   if(f==0)
      |   ^~

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