#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;
const double E = 1e-12;
inline
int dblcmp(double x)
{
 if (x > - E && x < E)
 return 0;
 return x > 0 ? 1 : -1;
}
int main()
{
 double num[5];
 while (true) {
 int cc = 0;
 for (int i = 0; i < 3; i++) {
 scanf("%lf", &num[i]);
 if (dblcmp(num[i]) == 0)
 cc++;
 }
 if (cc == 3) {
 break;
 }
 sort(num, num + 3);
 double t = num[0];
 long long h = floor(num[1] + 0.5), l = floor(num[2] + 0.5);
 bool ok = false;
 if (dblcmp(t - 0.25) >= 0 && h >= 90 && l >= 125) {
 if (dblcmp(7 - t) >= 0 && h <= 155 && l <= 290) {
 printf("letter\n");
 ok = true;
 } else {
 if (dblcmp(50 - t) >= 0 && h <= 300 && l <= 380) {
 printf("packet\n");
 ok = true;
 } else {
 double ans = t * 2 + (double)h * 2 + (double)l;
 if (dblcmp(ans - 2100) <= 0) {
 printf("parcel\n");
 ok = true;
 }
 }
 }
 }
 if (!ok) {
 printf("not mailable\n");
 }
 }
 return 0;
}