scara1.cpp: In function 'int main()': scara1.cpp:86: warning: unused variable 'b' scara1.cpp:87: warning: unused variable 'a' scara1.cpp:83: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result scara1.cpp:84: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result scara1.cpp:85: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result