pikachu.cpp: In function 'int main()': pikachu.cpp:158: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pikachu.cpp:159: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pikachu.cpp:160: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pikachu.cpp:163: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pikachu.cpp:181: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result