View Compilation Error

0_0_28252697_26813.cpp: In function 'int main()':
0_0_28252697_26813.cpp:6:2: error: '_int64' was not declared in this scope
  _int64 n,m;
  ^
0_0_28252697_26813.cpp:7:28: error: 'n' was not declared in this scope
  while(scanf("%I64d%I64d",&n,&m)&&(n||m)){
                            ^
0_0_28252697_26813.cpp:7:31: error: 'm' was not declared in this scope
  while(scanf("%I64d%I64d",&n,&m)&&(n||m)){
                               ^