proc ShowPosn(N);       \Show row and column for element
int  N, M, A, B, I, R, C;
[A:= [ 1,  2,  5, 13, 57, 72, 89, 104]; \magic numbers
 B:= [-1, 15, 25, 35, 72, 21, 58,   7];
I:= 7;
while A(I) > N do I:= I-1;
M:= N + B(I);
R:= M/18 +1;
C:= rem(0) +1;
IntOut(0, N);  Text(0, " -> ");
IntOut(0, R);  Text(0, ", ");
IntOut(0, C);  CrLf(0);
];

int Element, I;
[Element:= [1, 2, 29, 42, 57, 58, 72, 89, 90, 103];
for I:= 0 to 10-1 do ShowPosn(Element(I));
]