View Compilation Error

0_0_7717738_27694.cpp: In function `int main()':
0_0_7717738_27694.cpp:19: error: `j' undeclared (first use this function)
0_0_7717738_27694.cpp:19: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7717738_27694.cpp:19: error: `n' undeclared (first use this function)
0_0_7717738_27694.cpp:20: error: `m' undeclared (first use this function)