View Compilation Error

0_0_8723906_9143.cpp:12:20: system.h: No such file or directory
0_0_8723906_9143.cpp: In function `void input(int&)':
0_0_8723906_9143.cpp:41: error: `getchar_unlocked' undeclared (first use this function)
0_0_8723906_9143.cpp:41: error: (Each undeclared identifier is reported only once for each function it appears in.)