#include <stdio.h>
int main() {
    int s, m;
    scanf("%d", &s);
    if (1 <= s && s <= 1800) {
        if (s % 60 != 0)
            m = s / 60 + 1;
        else
            m = s / 60;
    }
    printf("%d\n", m);
    return 0;
}