ec.cpp: In function `long long int strtoi(int&)': ec.cpp:23: warning: comparison between signed and unsigned integer expressions ec.cpp: In function `int main()': ec.cpp:67: warning: comparison between signed and unsigned integer expressions ec.cpp:78: warning: comparison between signed and unsigned integer expressions ec.cpp:82: warning: comparison between signed and unsigned integer expressions ec.cpp:57: warning: unused variable `long long int free' ec.cpp:104:2: warning: no newline at end of file