recursion.cpp

#include <stdio.h>

int recursion(int n)
{
    if (n == 1) return 7;
    return recursion(n-1) + 5;
}

int main()
{
    int N;
    while(scanf("%d", &N), N != 0) {
        printf("%d\n", recursion(N));
    }

    return 0;
}