foo.cc: In function 'int main()':
foo.cc:9:22: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
    9 |         for(int i=0;i<strlen(ch1);i++)
      |                     ~^~~~~~~~~~~~
foo.cc:11:22: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   11 |         for(int i=0;i<strlen(ch2);i++)
      |                     ~^~~~~~~~~~~~

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