View Compilation Error

0_0_6416817_31848.cpp: In function `int main()':
0_0_6416817_31848.cpp:29: error: `sum2kk' undeclared (first use this function)
0_0_6416817_31848.cpp:29: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6416817_31848.cpp:29: error: expected `;' before ']' token