#include<stdio.h>intmain(){
int input_num;
scanf("%d", &input_num);
int i;
int num;
num = 0;
for (i = 1; i <= input_num; ++i) {
if ((i % 4 == 0 && i % 100 != 0) || i % 400 == 0) {
num++;
} else {
num = num;
}
}
printf("The number of leap years is %d.", num);
return0;
}