View Compilation Error

66785_0_7998.cpp:4: error: `_int64' does not name a type
66785_0_7998.cpp: In function `int main()':
66785_0_7998.cpp:35: error: `MaxSumEx' undeclared (first use this function)
66785_0_7998.cpp:35: error: (Each undeclared identifier is reported only once for each function it appears in.)