View Compilation Error

0_0_4081887_7051.cpp: In function `int main()':
0_0_4081887_7051.cpp:16: error: `scanf' undeclared (first use this function)
0_0_4081887_7051.cpp:16: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4081887_7051.cpp:19: error: `puts' undeclared (first use this function)