concurs.cpp: In function 'int main()': concurs.cpp:9: warning: unused variable 'pp' concurs.cpp:9: warning: unused variable 'k' concurs.cpp:9: warning: unused variable 'l' concurs.cpp:7: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result concurs.cpp:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result concurs.cpp:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result concurs.cpp:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result concurs.cpp:9: warning: 'j1' may be used uninitialized in this function concurs.cpp:9: warning: 'j2' may be used uninitialized in this function