View Compilation Error

0_0_2016759_27358.cpp: In function `int f(int)':
0_0_2016759_27358.cpp:4: error: `sqrt' undeclared (first use this function)
0_0_2016759_27358.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2016759_27358.cpp: In function `int main()':
0_0_2016759_27358.cpp:13: error: `cin' undeclared (first use this function)
0_0_2016759_27358.cpp:17: error: `printf' undeclared (first use this function)
0_0_2016759_27358.cpp:19: error: `system' undeclared (first use this function)