View Compilation Error

192083_0_19623.cpp: In function `int main()':
192083_0_19623.cpp:6: error: `sum' undeclared (first use this function)
192083_0_19623.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
192083_0_19623.cpp:7: error: expected `;' before "sum"