View Compilation Error

0_0_38151118_29114.cpp: In function 'int main()':
0_0_38151118_29114.cpp:47:32: error: 'year' was not declared in this scope
     while ((scanf("%d %d %d", &year, &mon, &day)) != -1) {
                                ^
0_0_38151118_29114.cpp:47:39: error: 'mon' was not declared in this scope
     while ((scanf("%d %d %d", &year, &mon, &day)) != -1) {
                                       ^
0_0_38151118_29114.cpp:47:45: error: 'day' was not declared in this scope
     while ((scanf("%d %d %d", &year, &mon, &day)) != -1) {
                                             ^