View Compilation Error

0_0_13039234_9793.cpp: In function `long long int mod_exp(long long int, long long int, long long int)':
0_0_13039234_9793.cpp:16: error: invalid token
0_0_13039234_9793.cpp:16: error: non-lvalue in unary `&'
0_0_13039234_9793.cpp:16: error: expected `)' before ';' token
0_0_13039234_9793.cpp:16: error: expected `;' before ')' token