View Compilation Error

0_0_4169569_16612.cpp: In function `int main()':
0_0_4169569_16612.cpp:1: error: `scanf' undeclared (first use this function)
0_0_4169569_16612.cpp:1: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4169569_16612.cpp:1: error: `printf' undeclared (first use this function)
0_0_4169569_16612.cpp:1: error: `putchar' undeclared (first use this function)