View Compilation Error

65835_0_6701.cpp: In function `int main()':
65835_0_6701.cpp:16: error: `e' undeclared (first use this function)
65835_0_6701.cpp:16: error: (Each undeclared identifier is reported only once for each function it appears in.)
65835_0_6701.cpp:16: error: `d' undeclared (first use this function)