foo.cc: In function 'long long unsigned int cnt(long long unsigned int)':
foo.cc:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'long long unsigned int' [-Wsign-compare]
   10 |     for (int i = 1; i <=n; i++) {
      |                     ~~^~~
foo.cc: In function 'int main()':
foo.cc:22:12: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long unsigned int*' [-Wformat=]
   22 |    scanf("%d",&n);
      |           ~^  ~~
      |            |  |
      |            |  long long unsigned int*
      |            int*
      |           %lld
foo.cc:22:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |    scanf("%d",&n);
      |    ~~~~~^~~~~~~~~

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