foo.cc: In function 'int main()':
foo.cc:4:30: warning: variable 'c' set but not used [-Wunused-but-set-variable]
    4 |         int i, n, m[100000], c;
      |                              ^
foo.cc:28:19: warning: 'b' may be used uninitialized [-Wmaybe-uninitialized]
   28 |                 y = y * b;
      |                 ~~^~~~~~~
foo.cc:8:23: note: 'b' was declared here
    8 |         int a = m[i], b;
      |                       ^

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