foo.cc: In function 'int main()':
foo.cc:6:13: warning: 'a' is used uninitialized [-Wuninitialized]
    6 |         if(a%5==0&&a%7==0)
      |            ~^~
foo.cc:5:13: note: 'a' was declared here
    5 |         int a;
      |             ^

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