View Compilation Error

0_0_19355182_11681.cpp: In function 'int main()':
0_0_19355182_11681.cpp:17:17: error: 'ans' was not declared in this scope
                 ans=ans+a[i]-s;
                 ^
0_0_19355182_11681.cpp:20:23: error: 'ans' was not declared in this scope
         printf("%d\n",ans);
                       ^
0_0_19355182_11681.cpp: At global scope:
0_0_19355182_11681.cpp:22:5: error: expected unqualified-id before 'return'
     return 0;
     ^
0_0_19355182_11681.cpp:23:1: error: expected declaration before '}' token
 }
 ^