pestera.cpp: In function 'void read()': pestera.cpp:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pestera.cpp:31: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result pestera.cpp:45: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result pestera.cpp: In function 'void solve()': pestera.cpp:93: warning: comparison between signed and unsigned integer expressions pestera.cpp: In function 'int main()': pestera.cpp:135: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pestera.cpp:136: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result In file included from /usr/include/stdio.h:910, from pestera.cpp:1: In function 'char* fgets(char*, int, FILE*)', inlined from 'void read()' at pestera.cpp:31: /usr/include/bits/stdio2.h:253: warning: call to '__fgets_chk_warn' declared with attribute warning: fgets called with bigger size than length of destination buffer In function 'char* fgets(char*, int, FILE*)', inlined from 'void read()' at pestera.cpp:45: /usr/include/bits/stdio2.h:253: warning: call to '__fgets_chk_warn' declared with attribute warning: fgets called with bigger size than length of destination buffer