View Compilation Error

0_0_11109247_4709.cpp: In function `long long int mod_exp(long long int, long long int, long long int)':
0_0_11109247_4709.cpp:20: error: stray '\168' in program
0_0_11109247_4709.cpp:20: error: `Ci' undeclared (first use this function)
0_0_11109247_4709.cpp:20: error: (Each undeclared identifier is reported only once for each function it appears in.)