#include <stdlib.h>
#include <stdio.h>
using namespace std;
#define z5                   1
#define z25                 6
#define z125               31
#define z625               156
#define z3125             781
#define z15625           3906
#define z78125           19531
#define z390625         97656
#define z1953125       488281
#define z9765625       2441406
#define z48828125     12207031
#define z244140625   61035156
#define z1220703125 305175781

long p;
long rez = 0;
FILE *fin, *fout;

void rezolva()
{
     if (p < 1) { }
     else if (p < 6) { p--; rez = p * 5 + 5; }
     else if (p < 31) { p-=6; rez = p * 5 + 25; }
}

int main()
{
    fin = fopen("fact.in", "r");
    fout = fopen("fact.out", "w");
    fscanf(fin, "%d", &p);
    rezolva();
    fprintf(fout, "%d", rez);
    fclose(fin); fclose(fout);
    return 0;
}