View Compilation Error

0_0_33533003_31339.cpp: In function 'int main()':
0_0_33533003_31339.cpp:35:4: error: 'x' was not declared in this scope
    x=(ksm(x,n)-1)*ksm(x-1,mod-2)%mod;
    ^
0_0_33533003_31339.cpp:39:3: error: 'ans' was not declared in this scope
   ans=ans*ksm(S,k)%mod;
   ^
0_0_33533003_31339.cpp: At global scope:
0_0_33533003_31339.cpp:43:2: error: expected unqualified-id before 'return'
  return 0;
  ^
0_0_33533003_31339.cpp:44:1: error: expected declaration before '}' token
 } 
 ^