View Compilation Error

0_0_15487269_11306.cpp: In function 'int main()':
0_0_15487269_11306.cpp:8:5: error: expected '(' before 'a'
  if a<=n
     ^
0_0_15487269_11306.cpp:11:2: error: 'else' without a previous 'if'
  else
  ^
0_0_15487269_11306.cpp:12:16: error: 'd' was not declared in this scope
  printf("%d\n",d)
                ^