#!/usr/bin/python
# xisk - May 2013
# Python 2.7.3
# License: Creative Commons BY-ND 3.0

def lpf(x):
    lpf = 2;
    while (x > lpf):
        if (x%lpf==0):
            x = x/lpf
            lpf = 2
        else:
            lpf+=1;
    print("Largest Prime Factor: %d" % (lpf));

def main():
    x = long(raw_input("Input long int:"))
    lpf(x);
    return 0;

if __name__ == '__main__':
    main()