View Compilation Error

0_0_2709141_15754.cpp: In function `int main()':
0_0_2709141_15754.cpp:7: error: `a' undeclared (first use this function)
0_0_2709141_15754.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2709141_15754.cpp:12: error: `i' undeclared (first use this function)
0_0_2709141_15754.cpp:19: error: `j' undeclared (first use this function)