piata.cpp: In function 'int main()': piata.cpp:15: warning: unused variable 'i' piata.cpp:15: warning: unused variable 'j' piata.cpp:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result piata.cpp:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result piata.cpp:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result piata.cpp:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result piata.cpp:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result