View Compilation Error

0_0_31642392_18278.cpp: In function 'int main()':
0_0_31642392_18278.cpp:6:3: error: '_int64' was not declared in this scope
   _int64 a,b;
   ^
0_0_31642392_18278.cpp:7:8: error: 'a' was not declared in this scope
   cin>>a>>b;
        ^
0_0_31642392_18278.cpp:7:11: error: 'b' was not declared in this scope
   cin>>a>>b;
           ^
0_0_31642392_18278.cpp:36:11: error: expected ';' before 'c1'
    _int64 c1=2;
           ^
0_0_31642392_18278.cpp:38:5: error: 'c1' was not declared in this scope
     c1=c1*2;
     ^
0_0_31642392_18278.cpp:39:4: error: 'c1' was not declared in this scope
    c1-=1;
    ^
0_0_31642392_18278.cpp:40:11: error: expected ';' before 'c2'
    _int64 c2=(c1+1)*(-1);
           ^
0_0_31642392_18278.cpp:41:11: error: expected ';' before 'c'
    _int64 c=a+b;
           ^
0_0_31642392_18278.cpp:42:7: error: 'c' was not declared in this scope
    if(c>c1||c<c2)
       ^
0_0_31642392_18278.cpp:42:15: error: 'c2' was not declared in this scope
    if(c>c1||c<c2)
               ^