diff --git a/README.md b/README.md
index ae0409d..d32750d 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,5 @@ by Tim Roughgarden from the Stanford University. I implemented the assignments
 in Rust to learn more about the language. I took the class to refresh my
 knowledge about algorithms.
 
+[Certificate](https://coursera.org/share/8af17a8221800221c68a8d7bfb69fd88)
+
diff --git a/src/main.rs b/src/main.rs
index ca93a77..c96c5bd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -170,6 +170,7 @@ fn c4a3() {
     let g = util::read_tsp_graph("data/c4a3_tsp.txt").unwrap();
     let r = tsp_heuristic(g);
     println!("r = {}", r);
+    // r = 1203406
 }
 
 #[allow(dead_code)]
@@ -180,6 +181,7 @@ fn c4a4() {
         let r = sat2(s);
         println!("{} = {}", f, r);
     }
+    // r = 101100
 }
 
 fn main() {
diff --git a/src/papadimitriou.rs b/src/papadimitriou.rs
index b7843df..a4cc2f7 100644
--- a/src/papadimitriou.rs
+++ b/src/papadimitriou.rs
@@ -25,13 +25,14 @@ fn get_random_assignment(n_clauses: usize) -> Vec<bool> {
 
 pub fn sat2(s: Sat2) -> bool {
     let n_clauses: f64 = s.n_clauses as f64;
-    let outer_repeats: usize =  n_clauses.log(2.0).ceil() as usize;
-    let inner_repeats: usize = 2 * s.n_clauses * s.n_clauses;
+    let outer_repeats: usize = n_clauses.log(2.0).ceil() as usize;
+    let inner_repeats: usize = 2 * s.n_clauses;
     let mut rng = rand::thread_rng();
 
     for _ in 0..outer_repeats {
         let mut a = get_random_assignment(s.n_clauses);
-        for _ in 0..inner_repeats {
+        let mut i = 0;
+        while i < inner_repeats {
             let mut valid = true;
             for c in &s.clauses {
                 if a[c.v1] == c.n1 || a[c.v2] == c.n2 {
@@ -45,7 +46,7 @@ pub fn sat2(s: Sat2) -> bool {
                         a[c.v2] = !a[c.v2];
                     }
                     valid = false;
-                    break;
+                    i += 1;
                 }
             }
             if valid {