View Compilation Error

0_0_4083858_31243.cpp: In function `int main()':
0_0_4083858_31243.cpp:4: error: `scanf' undeclared (first use this function)
0_0_4083858_31243.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4083858_31243.cpp:4: error: `EOF' undeclared (first use this function)
0_0_4083858_31243.cpp:6: error: `cout' undeclared (first use this function)
0_0_4083858_31243.cpp:6: error: `a' undeclared (first use this function)
0_0_4083858_31243.cpp:6: error: `b' undeclared (first use this function)
0_0_4083858_31243.cpp:6: error: `endl' undeclared (first use this function)