Edsger Wybe Dijkstra, at the Mathematisch Centrum in Amsterdam, designed in 1956 — and published in 1959 in "A Note on Two Problems in Connexion with Graphs" — a method for finding the lowest-cost route between two points in a graph with non-negative edge weights, systematically and efficiently considering all possible paths without needing to examine them exhaustively one by one. As Dijkstra himself recounted in later interviews, he conceived the algorithm on an Amsterdam terrace in about twenty minutes, without paper or pencil, as a mental exercise to demonstrate the capabilities of the ARMAC computer his institute had just acquired, choosing the shortest-route problem between Rotterdam and Groningen as an understandable demonstration for the general public. The algorithm becomes the foundation of packet-routing systems in telecommunications networks and, decades later, the core of GPS navigation systems and route planning in digital maps. Dijkstra is also, independently of this work, the author of the influential essay "Go To Statement Considered Harmful" (1968), which drives the structured programming movement by arguing that indiscriminate use of unconditional jump instructions (GOTO) makes code difficult to verify and reason about formally.