pavare1.cpp: In function 'int main()': pavare1.cpp:3: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pavare1.cpp:4: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pavare1.cpp:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pavare1.cpp:5: warning: 'nr2' may be used uninitialized in this function