char.cpp: In function 'int main()': char.cpp:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result char.cpp:21: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result char.cpp:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result char.cpp:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result char.cpp:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result