diff --git a/exo4-codage-lisp/couples.c b/exo4-codage-lisp/couples.c
new file mode 100644
index 0000000..fd00182
--- /dev/null
+++ b/exo4-codage-lisp/couples.c
@@ -0,0 +1,148 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int pair(int x){
+	return (!(x % 2));
+}
+
+int code_couples_very_slow(int _x, int _y){
+	int x, y;
+	x = y = 0;
+	int code = 0;
+	char direction = 'r'; // 'l' pour "left-down", 'r' pour "right-up"
+	printf("In the 'couples' function\n");
+	sleep(1);
+	while(((x != _x) || (y != _y))){
+		if((y == 0) && (pair(x))){
+			printf("IF1:\n");	
+			sleep(1);		
+			x++;
+			code++;
+			direction = 'l';
+			printf("IF N° 1, x = %d, y = %d, code = %d\n", x, y, code);
+			sleep(1);
+		}
+		else if((x == 0) && (!pair(y))){
+			printf("IF2:\n");			
+			sleep(1);
+			y++;
+			code++;
+			direction = 'r';	
+			printf("IF N° 2, x = %d, y = %d, code = %d\n", x, y, code);
+			sleep(1);
+		}
+		else if((y == 0) && (direction == 'l')){
+			printf("IF3:\n");
+			sleep(1);			
+			while((x != 0) && ((x != _x) || (y != _y))){
+				printf("WHILE3:\n");
+				sleep(1);
+				x--;
+				y++;
+				code++;
+				printf("IF N° 3, x = %d, y = %d, code = %d\n", x, y, code);
+				sleep(1);
+			}
+		}
+		else if((x == 0) && (direction == 'r')){
+			printf("IF4:\n");			
+			sleep(1);
+			while((y != 0) && ((x != _x) || (y != _y))){
+				printf("WHILE4:\n");
+				sleep(1);
+				x++;
+				y--;
+				code++;
+				printf("IF N° 4, x = %d, y = %d, code = %d\n", x, y, code);
+				sleep(1);
+			}
+		}
+	} 
+	return code;
+}
+
+int code_couples_slow(int _x, int _y){
+	int x, y;
+	x = y = 0;
+	int code = 0;
+	char direction = 'r'; // 'l' pour "left-down", 'r' pour "right-up"
+	while(((x != _x) || (y != _y))){
+		if((y == 0) && (pair(x))){
+			x++;
+			code++;
+			direction = 'l';
+		}
+		else if((x == 0) && (!pair(y))){
+			y++;
+			code++;
+			direction = 'r';	
+		}
+		else if((y == 0) && (direction == 'l')){
+			while((x != 0) && ((x != _x) || (y != _y))){
+				x--;
+				y++;
+				code++;
+			}
+		}
+		else if((x == 0) && (direction == 'r')){
+			while((y != 0) && ((x != _x) || (y != _y))){
+				x++;
+				y--;
+				code++;
+			}
+		}
+	} 
+	return code;
+}
+
+
+int code_couples_faster(int _x, int _y){
+	int x, y;
+	x = y = 0;
+	int code = 0;
+	int incr_int = 0;
+	char direction = 'r'; // 'l' pour "left-down", 'r' pour "right-up"
+	while(((x != _x) || (y != _y))){
+		if((y == 0) && (pair(x))){
+			x++;
+			code++;
+			incr_int++;
+			direction = 'l';
+		}
+		else if((x == 0) && (!pair(y))){
+			y++;
+			code++;
+			incr_int++;
+			direction = 'r';	
+		}
+		else if((y == 0) && (direction == 'l')){
+			while((x != 0) && ((x != _x) || (y != _y))){
+				x--;
+				y++;
+				code++;
+			}
+		}
+		else if((x == 0) && (direction == 'r')){
+			while((y != 0) && ((x != _x) || (y != _y))){
+				x++;
+				y--;
+				code++;
+			}
+		}
+	} 
+	return code;
+}
+
+
+
+
+int main(int argc, char **argv, char **envp){
+	printf("hello\n");
+	int code = 0;	
+	int x, y, z;
+	x = 11;
+	y = 5;
+	//z = -2;
+	code = code_couples_slow(x,y);
+	printf("Le code du couple (%d, %d) est %d\n", x, y, code);
+}