View Compilation Error

0_0_29449157_18891.cpp: In function 'int main()':
0_0_29449157_18891.cpp:22:2: error: expected '(' before 'while'
  while(n--){
  ^
0_0_29449157_18891.cpp:22:2: error: expected primary-expression before 'while'
0_0_29449157_18891.cpp:22:2: error: expected ')' before 'while'