View Compilation Error

0_0_6247142_20286.cpp: In function `int main()':
0_0_6247142_20286.cpp:6: error: `n' undeclared (first use this function)
0_0_6247142_20286.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6247142_20286.cpp:6: error: `p' undeclared (first use this function)
0_0_6247142_20286.cpp:6: error: `q' undeclared (first use this function)