View Compilation Error

0_0_6940645_2877.cpp:4: error: expected init-declarator before numeric constant
0_0_6940645_2877.cpp:4: error: expected `,' or `;' before numeric constant
0_0_6940645_2877.cpp: In function `int main()':
0_0_6940645_2877.cpp:10: error: `MAXN' undeclared (first use this function)
0_0_6940645_2877.cpp:10: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6940645_2877.cpp:11: error: `a' undeclared (first use this function)
0_0_6940645_2877.cpp:12: error: `b' undeclared (first use this function)
0_0_6940645_2877.cpp:13: error: `sum' undeclared (first use this function)
0_0_6940645_2877.cpp:20: error: `A' undeclared (first use this function)
0_0_6940645_2877.cpp:21: error: `B' undeclared (first use this function)