foo.cc: In function 'int main()':
foo.cc:21:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |                         for (int i = 0; i < v.size(); i++) {
      |                                         ~~^~~~~~~~~~
foo.cc:17:13: warning: unused variable 'res' [-Wunused-variable]
   17 |         int res = 0, t = m;
      |             ^~~
foo.cc:17:22: warning: unused variable 't' [-Wunused-variable]
   17 |         int res = 0, t = m;
      |                      ^

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