foo.cc: In function 'int main()':
foo.cc:15:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   a[i+1]=gcd(a[i],a[i+1]);
   ~~~~~~^~~~~~~~~~~~~~~~~
foo.cc: In function 'int gcd(int, int)':
foo.cc:26:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return ans;
         ^~~

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