View Compilation Error

0_0_32853764_23581.cpp: In function 'int main()':
0_0_32853764_23581.cpp:21:5: error: '_int64' was not declared in this scope
     _int64 a,b,ansa,ansb;
     ^
0_0_32853764_23581.cpp:29:9: error: 'ansa' was not declared in this scope
         ansa=ansb=0;
         ^
0_0_32853764_23581.cpp:29:14: error: 'ansb' was not declared in this scope
         ansa=ansb=0;
              ^
0_0_32853764_23581.cpp:32:29: error: 'a' was not declared in this scope
         scanf("%I64d%I64d",&a,&b);
                             ^
0_0_32853764_23581.cpp:32:32: error: 'b' was not declared in this scope
         scanf("%I64d%I64d",&a,&b);
                                ^