Compilare: main.cpp: In function 'int main()': main.cpp:7:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "adunare.in" , "r" , stdin ) ; ^ main.cpp:8:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "adunare.out" , "w" , stdout ) ; ^ main.cpp:12:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d" , & a , & b ) ; ^