View Compilation Error

0_0_13243894_23509.cpp: In function 'int main()':
0_0_13243894_23509.cpp:13:2: error: '_int64' was not declared in this scope
  _int64 t,res;
  ^
0_0_13243894_23509.cpp:15:9: error: expected ';' before 'a'
  _int64 a[21]={1,1,2};
         ^
0_0_13243894_23509.cpp:18:3: error: 'a' was not declared in this scope
   a[i]=(i)*(a[i-1]+a[i-2]);
   ^
0_0_13243894_23509.cpp:23:3: error: 'res' was not declared in this scope
   res=0;
   ^
0_0_13243894_23509.cpp:25:3: error: 't' was not declared in this scope
   t=fact(n,m);
   ^
0_0_13243894_23509.cpp:26:9: error: 'a' was not declared in this scope
   res=t*a[m-1];
         ^