View Compilation Error

0_0_37773766_23626.cpp: In function 'int main()':
0_0_37773766_23626.cpp:54:9: error: '_' was not declared in this scope
     rep(_,1,rdi)
         ^
0_0_37773766_23626.cpp:54:13: error: 'rdi' was not declared in this scope
     rep(_,1,rdi)
             ^
0_0_37773766_23626.cpp:54:16: error: 'rep' was not declared in this scope
     rep(_,1,rdi)
                ^