#include #include int gcd (int n, int d) { if (n > d) return gcd (n-d, d); if (n < d) return gcd (n, d-n); else return n; } int main (int argc, char* argv[]) { int productNumerator = 1; int productDenominator = 1; for (int i = 1; i <= 9; i++) { for (int j = 1; j <= i; j++) { for (int k = 1; k <= 9; k++) { int numerator = j * 10 + i; int denominator = i * 10 + k; if (denominator >= numerator && denominator != numerator && denominator * j == numerator * k) { productNumerator *= numerator; productDenominator *= denominator; } } } } int greatestCommonDivisor = gcd (productNumerator, productDenominator); printf ("%d\n", productDenominator / greatestCommonDivisor); }