Add multilingual language and systems learning tracks

ceb/c-practice-20261101/lesson-3/main.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <assert.h>
+int remaining(int total, int done) { return done >= total ? 0 : total - done; }
+int main(void) {
+    assert(remaining(4,1)==3);
+    assert(remaining(4,4)==0);
+    assert(remaining(4,5)==0);
+    assert(remaining(0,0)==0);
+    puts("Nipasar");
+    return 0;
+}