lac.cpp: In function 'int main()': lac.cpp:10: warning: suggest explicit braces to avoid ambiguous 'else' lac.cpp:6: warning: unused variable 'x1' lac.cpp:4: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result lac.cpp:5: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result lac.cpp:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result lac.cpp:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result