View Compilation Error

0_0_31458256_32134.c: In function 'main':
0_0_31458256_32134.c:28:24: error: expected expression before '/' token
         scanf("%s",a1);//????????a1
                        ^
0_0_31458256_32134.c:30:23: error: expected expression before '/' token
         ka=strlen(a1);//?a1??
                       ^
0_0_31458256_32134.c:34:33: error: expected expression before '/' token
             a[i]=a1[ka-i-1]-'0';//a1?????????????????a??
                                 ^
0_0_31458256_32134.c:42:33: error: expected expression before '/' token
             b[i]=b1[kb-i-1]-'0';//b1?????????????????b??
                                 ^
0_0_31458256_32134.c:50:9: error: 'else' without a previous 'if'
         else
         ^
0_0_31458256_32134.c:56:28: error: expected expression before '/' token
             c[i]=a[i]+b[i];//????,??????????
                            ^