instructions = [l.split(" ") for l in open("input", "r").read().split("\n") if l]
instructions = [(operation, int(argument)) for (operation, argument) in instructions]
#jumpsto = {i: set() for i in range(0, len(instructions)+1)}
#jumpsfrom = {i: set() for i in range(0, len(instructions)+1)}

def follow(i, changed, visited):
    if i == len(instructions):
        print("changed", changed)
        return
    if i in visited:
        return
    (opcode, p) = instructions[i]
    visited = visited + [i]
    if opcode == "nop":
        follow(i + 1, changed, visited)
        if not changed:
            follow(i + p, i, visited)
    if opcode == "jmp":
        if not changed:
            follow(i + 1, i, visited)
        follow(i + p, changed, visited)
    elif opcode == "acc":
        follow(i + 1, changed, visited)

follow(0, 0, [])