diff --git a/src/exec.c b/src/exec.c
index d467ff6..f251093 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -9,7 +9,6 @@
 extern AST* root;
 
 ASTNumData exec_expr(AST* ast) {
-    // ast_print(ast);
     log_dbg("Started execution.");
     switch (ast->type) {
         case AST_TYPE_CALL: return exec_call(ast);
@@ -22,47 +21,48 @@ ASTNumData exec_call(AST* ast) {
     log_dbg("Started call execution.");
     fflush(stdout);
     ASTCallData* calldata = (ASTCallData*)ast->data;
+    if (calldata->argc >= 1) {
     if (!strcmp(calldata->to, "sum")) {
-        double total = 0;
+        double total = exec_expr(calldata->argv[0]);
 
         for (
-            size_t i = 0;
+            size_t i = 1;
             i < calldata->argc;
             total += exec_expr(calldata->argv[i++])
         );
 
         return total;
     } else if (!strcmp(calldata->to, "sub")) {
-        double total = 0;
+        double total = exec_expr(calldata->argv[0]);
 
         for (
-            size_t i = 0;
+            size_t i = 1;
             i < calldata->argc;
             total -= exec_expr(calldata->argv[i++])
         );
 
         return total;
     } else if (!strcmp(calldata->to, "mul")) {
-        double total = 1;
+        double total = exec_expr(calldata->argv[0]);
 
         for (
-            size_t i = 0;
+            size_t i = 1;
             i < calldata->argc;
             total *= exec_expr(calldata->argv[i++])
         );
 
         return total;
     } else if (!strcmp(calldata->to, "div")) {
-        double total = 1;
+        double total = exec_expr(calldata->argv[0]);
 
         for (
-            size_t i = 0;
+            size_t i = 1;
             i < calldata->argc;
             total /= exec_expr(calldata->argv[i++])
         );
 
         return total;
-    }
+    }}
     return -1000;
 }