View Compilation Error

0_0_12133841_5933.cpp: In function `int main()':
0_0_12133841_5933.cpp:12: error: `n' undeclared (first use this function)
0_0_12133841_5933.cpp:12: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12133841_5933.cpp:12: error: `k' undeclared (first use this function)