def commonSubstrings(x,L,a):
    length=len(a)
    i=0
    run=0
    runner=0
    while i<length:
        if a[i]=="su+":
            run += 1
            while i+1 < length and a[i+1] == "su+":
                run += 1
                i += 1
                if run > runner:
                    runner = run
                else:
                    pass
            run = 0
        else:
            pass
        i += 1
    print(runner)