View Compilation Error

0_0_2283214_20493.cpp: In function `int main()':
0_0_2283214_20493.cpp:35: error: `d' undeclared (first use this function)
0_0_2283214_20493.cpp:35: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2283214_20493.cpp:36: error: `r' undeclared (first use this function)