charlie.cpp: In function 'int main()': charlie.cpp:10: warning: unused variable 'a' charlie.cpp:10: warning: unused variable 'b' charlie.cpp:13: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result charlie.cpp:14: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result charlie.cpp:15: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result charlie.cpp:20: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result