View Compilation Error

0_0_35434791_25554.cpp: In function 'int main()':
0_0_35434791_25554.cpp:20:9: error: unable to find numeric literal operator 'operator""O'
     c=c*2O%b;  
         ^
0_0_35434791_25554.cpp:20:9: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes