View Compilation Error

0_0_35329428_30991.cpp: In function 'int main()':
0_0_35329428_30991.cpp:6:2: error: '_int64' was not declared in this scope
  _int64 n,m;
  ^
0_0_35329428_30991.cpp:7:29: error: 'n' was not declared in this scope
   while(scanf("%I64d%I64d",&n,&m)&&(n||m)) {
                             ^
0_0_35329428_30991.cpp:7:32: error: 'm' was not declared in this scope
   while(scanf("%I64d%I64d",&n,&m)&&(n||m)) {
                                ^