View Compilation Error

0_0_32917733_8867.cpp: In function 'int main()':
0_0_32917733_8867.cpp:28:4: error: expected ';' before 'else'
    else if(i==n-1&&a[i]=='1'){
    ^
0_0_32917733_8867.cpp:33:4: error: 'else' without a previous 'if'
    else if(i!=0){
    ^