View Compilation Error

0_0_6673255_32677.cpp: In function `int main()':
0_0_6673255_32677.cpp:7: error: `scanf' undeclared (first use this function)
0_0_6673255_32677.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6673255_32677.cpp:8: error: `getchar' undeclared (first use this function)
0_0_6673255_32677.cpp:23: error: `printf' undeclared (first use this function)