prefix1.cpp: In function 'int main()': prefix1.cpp:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result prefix1.cpp:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result prefix1.cpp:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result prefix1.cpp:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result prefix1.cpp:35: warning: 'poz' may be used uninitialized in this function