View Compilation Error

0_0_9930776_26133.cpp: In function `int prime(int)':
0_0_9930776_26133.cpp:6: error: `sqrt' undeclared (first use this function)
0_0_9930776_26133.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9930776_26133.cpp: In function `int main()':
0_0_9930776_26133.cpp:22: error: expected `}' at end of input