View Compilation Error

0_0_10264571_23624.cpp: In function `int main()':
0_0_10264571_23624.cpp:6: error: invalid initializer
0_0_10264571_23624.cpp:13: error: `sum' undeclared (first use this function)
0_0_10264571_23624.cpp:13: error: (Each undeclared identifier is reported only once for each function it appears in.)