View Compilation Error

0_0_17398857_6249.cpp: In function 'int main()':
0_0_17398857_6249.cpp:12:27: error: expected primary-expression before '<' token
         scanf("%s",a);    <span style="white-space:pre">          </span>  
                           ^
0_0_17398857_6249.cpp:12:28: error: 'span' was not declared in this scope
         scanf("%s",a);    <span style="white-space:pre">          </span>  
                            ^
0_0_17398857_6249.cpp:13:15: error: expected primary-expression before '<' token
         ans=0;<span style="white-space:pre">              </span>//初始化  
               ^
0_0_17398857_6249.cpp:14:21: error: expected primary-expression before '<' token
         l=strlen(a);<span style="white-space:pre">            </span>//数组a中元素的个数  
                     ^
0_0_17398857_6249.cpp:15:21: error: 'i' was not declared in this scope
         for(int i=0;i<l;i++)<span style="white-space:pre">     </span>//依次扫描a中元素，注意必须从0开始，因为从零开始存数  
                     ^