n,q=list(map(int,input().split()))
a=[i==1 for i in input()]
for _ in range(q):
    t,x,y=list(map(int,input().split()))
    if t==1:
        a[x-1]=(y==1)
    elif 0 in a[x-1:y-1]:
        if a[y-1:x-1:-1].index(0)%2==0:
            print("F")
        else:
            print("S")
    else:
        if (x-y)%2==1:
            print ("F")
        else:
            print("S")