View Compilation Error

0_0_12690027_9410.cpp: In function `int M_maxsum(int, int)':
0_0_12690027_9410.cpp:8: error: `maxsum' undeclared (first use this function)
0_0_12690027_9410.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12690027_9410.cpp:12: error: `a' undeclared (first use this function)