View Compilation Error

0_0_2872793_5945.cpp: In function `int main()':
0_0_2872793_5945.cpp:5: error: `scanf' undeclared (first use this function)
0_0_2872793_5945.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2872793_5945.cpp:9: error: `sqrt' undeclared (first use this function)
0_0_2872793_5945.cpp:18: error: `printf' undeclared (first use this function)