placi.cpp: In function 'int main()': placi.cpp:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result placi.cpp:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result placi.cpp:50: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result placi.cpp:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result