View Compilation Error

0_0_3962169_20700.cpp: In function `int main()':
0_0_3962169_20700.cpp:4: error: `scanf' undeclared (first use this function)
0_0_3962169_20700.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_3962169_20700.cpp:24: error: `printf' undeclared (first use this function)
0_0_3962169_20700.cpp:27: error: `puts' undeclared (first use this function)